Who has been buying Tsurumi Manufacturing Co., Ltd. stock?

11 distinct investors have filed 18 disclosed large-shareholding filings in Tsurumi Manufacturing Co., Ltd. (6351), most recently on 2026-03-31. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.

How many insider filings does Tsurumi Manufacturing Co., Ltd. have?

Tsurumi Manufacturing Co., Ltd. has 18 buy-side and 13 sell-side disclosures on record, covering ¥9.0B ($58.0M) in total reported value, spanning 2022-11-04 to 2026-03-31.

Do insider buys in Japanese stocks predict returns?

Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

Tsurumi Manufacturing Co., Ltd. 6351

Company

株式会社鶴見製作所Tsurumi Manufacturing Co., Ltd.

Investors

Buys

Total Value

¥9.0B ($58.0M)

Avg Return

+60.49%

Last Filing

2026-03-31

Tsurumi Manufacturing Co., Ltd. (6351) has 18 disclosed large-shareholding filings and 13 disclosed disposals on record, filed by 11 distinct investors. Together those filings cover ¥9.0B ($58.0M) in reported transaction value. The earliest filing StockDrifts holds for Tsurumi Manufacturing Co., Ltd. is dated 2022-11-04; the most recent is 2026-03-31. Across these filings the average return since disclosure is +60.49%, measured from each filing date to the latest available close.

Price & insider activity (12 months)

Recent filings

Date	Type	Source	Insider	Purpose	Shares	Price at filing	Return	Value
2026-08-06	BUY	Market Buy	辻本治	activist	437.9K	¥2,410	+6.6%	¥73M ($474K)
2026-08-06	BUY	unknown	株式会社ダイコウ	strategic	2.3M	¥2,410	-	-
2026-08-06	BUY	Market Buy	辻本晃利	strategic	69.8K	¥2,410	+6.6%	¥37M ($237K)
2026-08-06	BUY	Market Buy	株式会社T’sコーポレーション	strategic	3.6M	¥2,410	+6.6%	¥649M ($4.2M)
2026-08-06	BUY	unknown	辻本恵利	strategic	305.5K	¥2,410	-	-
2026-06-18	BUY	Market Buy	ダルトン・インベストメンツ・インク(Dalton Investments, Inc.) Dalton Investments, Inc.	activist	7.0M	¥2,252	+14.1%	¥1.2B ($7.5M)
2026-03-31	BUY	Market Buy	ダルトン・インベストメンツ・インク(Dalton Investments, Inc.) Dalton Investments, Inc.	activist	6.4M	¥2,053	+25.1%	¥1.1B ($6.9M)
2025-11-05	BUY	Market Buy	辻本治 Osamu Tsujimoto	activist	407.2K	¥1,930	+33.1%	¥78M ($506K)
2025-11-05	SELL	Market Buy	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	0	¥1,930	-33.1%	¥2.0B ($12.6M)
2025-11-05	BUY	Market Buy	株式会社ダイコウ Daiko Co., Ltd.	strategic	2.3M	¥1,930	+33.1%	¥2.3B ($14.7M)
2025-11-05	BUY	negotiated	辻本治 Osamu Tsujimoto	activist	407.2K	¥1,930	+33.1%	¥78M ($506K)
2025-11-05	BUY	Market Buy	辻本恵利 Eri Tsujimoto	strategic	305.4K	¥1,930	+33.1%	¥39M ($253K)
2025-11-05	SELL	negotiated	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	0	¥1,930	-33.1%	¥2.0B ($12.6M)
2025-11-05	BUY	negotiated	株式会社ダイコウ Daiko Co., Ltd.	strategic	2.3M	¥1,930	+33.1%	¥2.3B ($14.7M)
2025-11-05	BUY	negotiated	辻本恵利 Eri Tsujimoto	strategic	305.4K	¥1,930	+33.1%	¥39M ($253K)
2024-05-20	BUY	Market Buy	辻本治 Osamu Tsujimoto	activist	197.5K	¥2,005	+28.1%	¥6M ($36K)
2024-05-20	BUY	negotiated	辻本治 Osamu Tsujimoto	activist	197.5K	¥2,005	+28.1%	¥6M ($36K)
2024-05-20	SELL	Market Buy	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	547.7K	¥2,005	-28.1%	¥695M ($4.5M)
2024-05-20	BUY	Market Buy	株式会社ダイコウ Daiko Co., Ltd.	strategic	579.7K	¥2,005	-	-
2024-05-20	BUY	Market Buy	辻本恵利 Eri Tsujimoto	strategic	152.7K	¥2,005	-	-
2024-05-20	SELL	negotiated	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	547.7K	¥2,005	-28.1%	¥695M ($4.5M)
2024-05-20	BUY	negotiated	株式会社ダイコウ Daiko Co., Ltd.	strategic	579.7K	¥2,005	-	-
2024-05-20	BUY	negotiated	辻本恵利 Eri Tsujimoto	strategic	152.7K	¥2,005	-	-
2024-02-08	SELL	negotiated	ダルトン・インベストメンツ・インク(Dalton Investments, Inc.) Dalton Investments, Inc.	activist	3.2M	¥1,765	-45.5%	¥49M ($313K)
2024-01-11	SELL	negotiated	ダルトン・インベストメンツ・エルエルシー Dalton Investments LLC	activist	0	¥1,940	-32.4%	¥6.0B ($38.5M)
2024-01-11	BUY	negotiated	ダルトン・インベストメンツ・インク(Dalton Investments Dalton Investments, Inc.	activist	3.2M	¥1,940	-	¥6.3B ($40.5M)
2023-01-31	BUY	unknown	ツルミ共栄会理事長九喜延之 kuki nobuyuki	strategic	1.7M	¥1,000	+156.9%	¥1.7B ($11.1M)
2023-01-31	SELL	unknown	ツルミ共栄会理事長九喜健三 Kenzo Kuki	strategic	0	¥1,000	-156.9%	¥1.7B ($10.8M)
2022-11-14	SELL	unknown	辻本晃利 Akitoshi Tsujimoto	strategic	30.0K	¥1,012	-153.8%	¥790M ($5.1M)
2022-11-14	BUY	unknown	株式会社T'sコーポレーション T's Corporation Co., Ltd.	strategic	1.8M	¥1,012	+153.8%	¥813M ($5.2M)
2022-11-14	BUY	unknown	株式会社T'sコーポレーション T's Corporation Co., Ltd.	strategic	1.8M	¥1,012	+153.8%	¥813M ($5.2M)
2022-11-14	SELL	unknown	辻本晃利 Akitoshi Tsujimoto	strategic	30.0K	¥1,012	-153.8%	¥790M ($5.1M)
2022-11-04	BUY	negotiated	辻本治 Osamu Tsujimoto	activist	195.0K	¥1,070	+140.1%	¥3M ($19K)
2022-11-04	SELL	Market Buy	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	894.7K	¥1,070	-140.1%	¥41M ($266K)
2022-11-04	SELL	Market Buy	株式会社有伸興産 Arishin Kosan Co., Ltd.	strategic	498	¥1,070	-140.1%	¥141M ($911K)
2022-11-04	SELL	negotiated	有限会社ツルミ興産 Tsurumi Kosan Co., Ltd.	strategic	894.7K	¥1,070	-140.1%	¥41M ($266K)
2022-11-04	BUY	Market Buy	株式会社ダイコウ Daiko Co., Ltd.	strategic	579.0K	¥1,070	+140.1%	¥150M ($968K)
2022-11-04	BUY	Market Buy	辻本恵利 Eri Tsujimoto	strategic	152.7K	¥1,070	+140.1%	¥3M ($19K)
2022-11-04	BUY	negotiated	株式会社ダイコウ Daiko Co., Ltd.	strategic	579.0K	¥1,070	+140.1%	¥150M ($968K)
2022-11-04	BUY	Market Buy	辻本治 Osamu Tsujimoto	activist	195.0K	¥1,070	+140.1%	¥3M ($19K)
2022-11-04	BUY	negotiated	辻本恵利 Eri Tsujimoto	strategic	152.7K	¥1,070	+140.1%	¥3M ($19K)
2022-11-04	SELL	negotiated	株式会社有伸興産 Arishin Kosan Co., Ltd.	strategic	498	¥1,070	-140.1%	¥141M ($911K)

Frequently asked questions

Who has been buying Tsurumi Manufacturing Co., Ltd. stock?: 11 distinct investors have filed 18 disclosed large-shareholding filings in Tsurumi Manufacturing Co., Ltd. (6351), most recently on 2026-03-31. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.
How many insider filings does Tsurumi Manufacturing Co., Ltd. have?: Tsurumi Manufacturing Co., Ltd. has 18 buy-side and 13 sell-side disclosures on record, covering ¥9.0B ($58.0M) in total reported value, spanning 2022-11-04 to 2026-03-31.
Do insider buys in Japanese stocks predict returns?: Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

More on this data

Every trade listed above comes from an official regulatory disclosure. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.