Japan - Miyazawa family of 4 murdered, Setagaya, Tokyo, 30 Dec 2000 #4

[Lalalacasbah]

We are still receiving news and updates about that one since it was only solved a month ago after 26 years, but the thread is way shorter than this so it should be easier to catch up.

In any case there are only very superficial similarities between that and the Miyazawa's. They are two very different cases.

Interesting to notice is that Satoru Takaba, the victim's husband, is the president of Sora no Kai of which An Irie is also a member of.
The two even know each other.

I am still reading the thread as I'm always lagging it seems

Would it be possible the Miyazawa's killer wanted to do a copycat murder after seeing this murder make headlines? Maybe so police would think it was the same killer so they copied some things? Or inspired by it somehow to act on their own compulsion?

Unsure what was all public at the time. The timing, similarities are definitely interesting especially the targeting of the main woman/mothers in the family/household.

And fascinating connection though... through the husband (and even An Irie depending how you look at it). I am not saying either is involved whatsoever as I know they are not - more a curious observation!:

• Husband is acquainted with An Irie
• Husband played tennis with his wife's killer, did An Irie, her husband or her children play tennis? I'm thinking not since husband wasn't living there long at the time
• Tennis was thought to be connected to Miyazawa's killer I believe because tennis courts and the Edwards Air Force base sand connection

All MOO JMO

 

[Eliver]

When I say that Satoru and An Irie know each other I mean they met through the Sora no Kai of course.

As like, they met because of the murders.
Together with many other members of bereaved families.

 

[Lalalacasbah]

When I say that Satoru and An Irie know each other I mean they met through the Sora no Kai of course.

As like, they met because of the murders.
Together with many other members of bereaved families.

Ohhhh I see. I didn't clue in the connection and had that mixed up. Thanks for clearing that up

 

[Sillybilly]

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[SHADOWW7]

Hey everyone!
I’ve been going through this case again and tried putting together a small theory. I know many of you here understand this case way better than I do, and I’m definitely not blaming anyone — just sharing thoughts.

I’m sure I’ve missed a lot of points and left a bunch of loopholes open… but still, what do you guys think?
What did I get wrong, what (if anything) sounds right, or is my whole theory just total nonsense?
Would love to hear your honest thoughts!



1. The Killer Feels Local — Not a Random Outsider

He entered through the skate-park side window, moved through the house confidently, stayed HOURS after the murders, used the family’s computer, ate ice cream, changed clothes, bandaged himself, slept on the sofa, etc.

This isn’t a “smash and grab.”
This feels like:

someone familiar with the Setagaya park layout

someone who knew that side was dark + quiet

someone comfortable enough to stay inside a murdered family’s home for a long time


This is very rare behavior.


---

2. Killer’s Shoes: Slazenger (Made in Korea, rare in Japan)

Police said the killer wore Slazenger sneakers — not very common in Japan in 2000.

These were:

usually sold through sports shops

often purchased by tennis players or people active in sports

also available in Harajuku’s Takeshita Street (famous for Korean imports)


Which connects to the next point…


---

3. Komazawa Olympic Park + University Connection

Miyazawa house → Komazawa Olympic Park → Komazawa University are all in the same broader area.

Komazawa Park in 2000 was:

heavily used by local college tennis teams

used by junior sports circuits

filled with students practicing skateboarding (outside the courts)

a hangout area for young athletes


It’s extremely close to Setagaya.

My thought:
Someone who used this area daily (tennis player or student) could have easily known the quiet window entry route, the blind spots, nighttime silence, etc.


---

4. The Sweatshirt Evidence (ONLY 10 Sold in ALL of Tokyo!)

This is a big detail that doesn’t get enough attention.

The killer left behind a light gray/purple sweatshirt. Police confirmed:

ONLY 10 pieces of this model were ever sold in Tokyo

ONLY 4 stores sold them (Ogikubo, Aoto, Seiseki-sakuragaoka, Hachioji)


Police found only 1 of the 10 buyers after the case.
9 purchasers remain unidentified.

One of these 9 has to be the killer.

Now here’s the important geographic clue:

The Ogikubo store is one of the closest to Komazawa/Setagaya area

Not next door, but close enough for a university student or athlete to visit on weekends — especially since Ogikubo is a popular youth shopping area.

This puts a potential suspect profile:

young male

active in sports

knows the area

shops in youth districts (Ogikubo, Harajuku)

possibly lives alone (no one noticed him returning injured or in different clothes)



---

5. Behavioral Clues Look Like an “Inexperienced but Physically Fit” Offender

He:

left his OWN blood everywhere

left clothes

left fingerprints

left bandages

used the PC

stayed hours

left the knife in the wounds

took nothing valuable except small money


This is not a professional hit.
This is someone young, impulsive, physically strong, and not very knowledgeable about forensic science.

A military person would NEVER leave so much DNA.
A gang member would not stick around for hours.
A random burglar would NOT kill 4 people (including kids).

But a young athletic guy, maybe 18–25, who lost control, possibly had an emotional trigger?

That fits surprisingly well.


---

6. Why a Tennis Player Could Fit (NOT accusing anyone, just logic)

✔ Strong build → matches the injuries

Yasuko’s injuries indicate a strong killer who used blunt force + choking + stabbing.

✔ Slazenger shoes → common in tennis players

Slazenger was widely used in tennis communities.

✔ Sweatshirt sold in youth stores → matches a student/college-age guy

All 4 stores were “young men’s casual fashion” shops.

✔ Komazawa Park proximity → routine familiarity with the area

Tennis players practiced there daily.

✔ Age profile matches police estimate (15–35, maybe younger side)

Junior tennis circuits (late teens / early 20s) fit perfectly.

✔ Possible emotional trigger

What if the Miyazawa father told some group of local skateboarders / park kids / sports guys to reduce noise?
This incident is documented.

A hot-headed young athlete could snap — especially if he felt insulted or humiliated.


---

7. Motive Possibilities (Not facts, just logical scenarios)

Scenario A: Noise Conflict With Local Youth

This is one of the few ACTUAL documented real-world tensions near the house.

What if the killer was part of that youth group?

Scenario B: Personal Grudge Against Mikio

Something said earlier in the park?
Something about the noise complaint?
A confrontation?

Scenario C: Aimless young man → explosion of violence

No motive, just rage and breakdown.

This has happened before in Japanese cases.


---

8. The Knife Purchase Angle

Someone purchased the same chef knife around the time of the murder.

Police said:

One person’s image appeared in the Kichijoji supermarket (north exit)

But they couldn't confirm him

Several buyers were identified but not the killer


This again places the killer in the Tokyo youth districts, possibly traveling for school, sports, or weekend outings.


---
MY CONCLUSION

When I combine ALL clues:

rare sports shoes

rare sweatshirt (only 10 sold)

purchasing knife in trendy youth area

familiarity with Setagaya route

comfort inside house

physical strength

emotional/impulsive brutality

no forced motive

long stay after crime

parks, universities, sports links in same radius


→ The “young Japanese male, possibly a local student or athlete (tennis/skateboarding)”
profile fits WAY more neatly than the military theory.


I know I’m not bringing anything new here — this case is 20+ years old and thousands of people have already thought of thousands of possibilities. I’m also just trying to look at it from a slightly different angle. Maybe I’m wrong, maybe the whole theory is useless, but I still wanted to share it and hear what you all think.

 

[WhoDisDoe]

Hey everyone!
I’ve been going through this case again and tried putting together a small theory. I know many of you here understand this case way better than I do, and I’m definitely not blaming anyone — just sharing thoughts.

I’m sure I’ve missed a lot of points and left a bunch of loopholes open… but still, what do you guys think?
What did I get wrong, what (if anything) sounds right, or is my whole theory just total nonsense?
Would love to hear your honest thoughts!



1. The Killer Feels Local — Not a Random Outsider

He entered through the skate-park side window, moved through the house confidently, stayed HOURS after the murders, used the family’s computer, ate ice cream, changed clothes, bandaged himself, slept on the sofa, etc.

This isn’t a “smash and grab.”
This feels like:

someone familiar with the Setagaya park layout

someone who knew that side was dark + quiet

someone comfortable enough to stay inside a murdered family’s home for a long time


This is very rare behavior.


---

2. Killer’s Shoes: Slazenger (Made in Korea, rare in Japan)

Police said the killer wore Slazenger sneakers — not very common in Japan in 2000.

These were:

usually sold through sports shops

often purchased by tennis players or people active in sports

also available in Harajuku’s Takeshita Street (famous for Korean imports)


Which connects to the next point…


---

3. Komazawa Olympic Park + University Connection

Miyazawa house → Komazawa Olympic Park → Komazawa University are all in the same broader area.

Komazawa Park in 2000 was:

heavily used by local college tennis teams

used by junior sports circuits

filled with students practicing skateboarding (outside the courts)

a hangout area for young athletes


It’s extremely close to Setagaya.

My thought:
Someone who used this area daily (tennis player or student) could have easily known the quiet window entry route, the blind spots, nighttime silence, etc.


---

4. The Sweatshirt Evidence (ONLY 10 Sold in ALL of Tokyo!)

This is a big detail that doesn’t get enough attention.

The killer left behind a light gray/purple sweatshirt. Police confirmed:

ONLY 10 pieces of this model were ever sold in Tokyo

ONLY 4 stores sold them (Ogikubo, Aoto, Seiseki-sakuragaoka, Hachioji)


Police found only 1 of the 10 buyers after the case.
9 purchasers remain unidentified.

One of these 9 has to be the killer.

Now here’s the important geographic clue:

The Ogikubo store is one of the closest to Komazawa/Setagaya area

Not next door, but close enough for a university student or athlete to visit on weekends — especially since Ogikubo is a popular youth shopping area.

This puts a potential suspect profile:

young male

active in sports

knows the area

shops in youth districts (Ogikubo, Harajuku)

possibly lives alone (no one noticed him returning injured or in different clothes)



---

5. Behavioral Clues Look Like an “Inexperienced but Physically Fit” Offender

He:

left his OWN blood everywhere

left clothes

left fingerprints

left bandages

used the PC

stayed hours

left the knife in the wounds

took nothing valuable except small money


This is not a professional hit.
This is someone young, impulsive, physically strong, and not very knowledgeable about forensic science.

A military person would NEVER leave so much DNA.
A gang member would not stick around for hours.
A random burglar would NOT kill 4 people (including kids).

But a young athletic guy, maybe 18–25, who lost control, possibly had an emotional trigger?

That fits surprisingly well.


---

6. Why a Tennis Player Could Fit (NOT accusing anyone, just logic)

✔ Strong build → matches the injuries

Yasuko’s injuries indicate a strong killer who used blunt force + choking + stabbing.

✔ Slazenger shoes → common in tennis players

Slazenger was widely used in tennis communities.

✔ Sweatshirt sold in youth stores → matches a student/college-age guy

All 4 stores were “young men’s casual fashion” shops.

✔ Komazawa Park proximity → routine familiarity with the area

Tennis players practiced there daily.

✔ Age profile matches police estimate (15–35, maybe younger side)

Junior tennis circuits (late teens / early 20s) fit perfectly.

✔ Possible emotional trigger

What if the Miyazawa father told some group of local skateboarders / park kids / sports guys to reduce noise?
This incident is documented.

A hot-headed young athlete could snap — especially if he felt insulted or humiliated.


---

7. Motive Possibilities (Not facts, just logical scenarios)

Scenario A: Noise Conflict With Local Youth

This is one of the few ACTUAL documented real-world tensions near the house.

What if the killer was part of that youth group?

Scenario B: Personal Grudge Against Mikio

Something said earlier in the park?
Something about the noise complaint?
A confrontation?

Scenario C: Aimless young man → explosion of violence

No motive, just rage and breakdown.

This has happened before in Japanese cases.


---

8. The Knife Purchase Angle

Someone purchased the same chef knife around the time of the murder.

Police said:

One person’s image appeared in the Kichijoji supermarket (north exit)

But they couldn't confirm him

Several buyers were identified but not the killer


This again places the killer in the Tokyo youth districts, possibly traveling for school, sports, or weekend outings.


---
MY CONCLUSION

When I combine ALL clues:

rare sports shoes

rare sweatshirt (only 10 sold)

purchasing knife in trendy youth area

familiarity with Setagaya route

comfort inside house

physical strength

emotional/impulsive brutality

no forced motive

long stay after crime

parks, universities, sports links in same radius


→ The “young Japanese male, possibly a local student or athlete (tennis/skateboarding)”
profile fits WAY more neatly than the military theory.


I know I’m not bringing anything new here — this case is 20+ years old and thousands of people have already thought of thousands of possibilities. I’m also just trying to look at it from a slightly different angle. Maybe I’m wrong, maybe the whole theory is useless, but I still wanted to share it and hear what you all think.

I think saying the killer was “comfortable” in the home is an assumption. Alternatively, they might’ve stayed in the house for so long because they were physically incapacitated from all the blood loss and needed time to recover. Them falling asleep could’ve been closer to “passing out” than to “having a nice nap”.

 

[SHADOWW7]

I think saying the killer was “comfortable” in the home is an assumption. Alternatively, they might’ve stayed in the house for so long because they were physically incapacitated from all the blood loss and needed time to recover. Them falling asleep could’ve been closer to “passing out” than to “having a nice nap”.

Thanks for sharing your POV — really appreciate it.
I actually agree with what you’re saying. ‘Comfortable’ probably wasn’t the right word from my side.

What I meant was: staying in the house for that long after such a brutal crime felt like a big risk. So it made me think the killer might’ve known the neighborhood well — like knowing it’s usually quiet, nobody checks in late at night, and the chances of someone noticing were low.

Not that they were relaxed, just that they felt the area was safe enough to hide and recover for a bit.
Because with injuries like that, staying inside a house with four victims is a huge risk for anyone.

 

[Eliver]

Probably repeating myself but just wanted to touch on a couple of points:

- Once again, the general theory is NOT that the perpetrator is/was a military. Simply the son of one.

- The perpetrator did NOT sleep on the sofa. Last year's documentary made it clear (and even showed it through pictures) that the murderer took a pillow from the sofa and laid down on the floor. For how long? We don't know of course. Could be hours, could be minutes or seconds. The police itself could not confirm how long (I'm guessing it's a fairly difficult thing to establish).

- The Ogikubo connection is well documented and was often discussed in these threads. Last page I posted a picture of the murder weapon that was (and still is) sold there. The picture was taken by user Incoherent and he originally posted it on thread 3.

- IIRC, the tennis court in Soshigaya Park offers (or at least it did at the time) a perfect view of the Miyazawa house. Hence the murderer might have seen the family and their habits from there.
Just to go back on the Yokota Air Base theory, the students from Yokota High School used to practice tennis and might have even used the court in Soshigaya (my speculation).

I don't currently live in Tokyo and I have only visited it a couple of times and I have never been to Kamisasoshigaya Park so maybe I'm missing some details.

 

[Incoherent]

It is interesting how the neighbourhood is described as both noisy and busy enough to have altercations with and noise complaints made about skateboarders and graffiti and trash everywhere, but also so deadly quiet and empty that someone can commit multiple murders after climbing in a window opposite a metropolitan road and in plain view without being seen or heard. So which one is it I wonder?
Not to mention the killer entered the house at a time when the lights were still on next door because the family were still awake and watching TV and he would have seen that. There were still people directly outside taking taxis and a manned police station was seconds away. A person that knew the neighbourhood well enough would know all this.

About universities, there were schools in the immediate area with student dormitories opposite the house in the baseball grounds. If I recall from historical maps there was even a dormitory next to the house at one point, but that was just before the family moved in. You wouldn’t need to travel any distance to come across students - they were already right there. It was also reported in Faceless that people came from all over Tokyo and further to use the facilities at Soshigaya Park, which included baseball grounds, skate park, athletic park, tennis courts, and the main Soshigaya park.

Simply put, there were a lot of different people around the immediate area at any given time and not all of them resided there.

 

[Incoherent]

Re: Ogikubo. I lived there for a few years around 2012, so quite far after the murders, but I wouldn’t describe it as a popular shopping place youngsters hang out. Shinjuku and central Tokyo is just 5 minutes away. Ogikubo is kinda boring actually and mostly residential.
However it is the one place so far that, at the time, every item of clothing and accessory he had, including the knife, could all be bought in the same building. It’s changed a lot now but the knife is still available for purchase in the Seiyu there. I wouldn’t be surprised if he did get some things in Ogikubo.