Who has been buying Toho System Science Co., Ltd. stock?

6 distinct investors have filed 4 disclosed large-shareholding filings in Toho System Science Co., Ltd. (4333), most recently on 2025-09-26. 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 Toho System Science Co., Ltd. have?

Toho System Science Co., Ltd. has 4 buy-side and 6 sell-side disclosures on record, covering ¥852M ($5.5M) in total reported value, spanning 2021-08-13 to 2025-09-26.

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.

Toho System Science Co., Ltd. 4333

Company

株式会社東邦システムサイエンスToho System Science Co., Ltd.

Investors

Buys

Total Value

¥852M ($5.5M)

Avg Return

+54.65%

Last Filing

2025-09-26

Toho System Science Co., Ltd. (4333) has 4 disclosed large-shareholding filings and 6 disclosed disposals on record, filed by 6 distinct investors. Together those filings cover ¥852M ($5.5M) in reported transaction value. The earliest filing StockDrifts holds for Toho System Science Co., Ltd. is dated 2021-08-13; the most recent is 2025-09-26. Across these filings the average return since disclosure is +54.65%, 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
2025-09-26	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	533.9K	¥1,264	-	-
2025-09-26	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,264	-	-
2025-09-26	BUY	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.3M	¥1,264	-	-
2025-09-26	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	61.6K	¥1,264	-	-
2025-09-26	BUY	Market Buy	株式会社エヌオーアイ NIO Co., Ltd.	passive	429.4K	¥1,264	-	-
2025-06-06	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,212	-	-
2025-06-06	SELL	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.3M	¥1,212	+5.6%	¥519M ($3.4M)
2025-06-06	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	61.6K	¥1,212	-	-
2025-06-06	BUY	Market Buy	株式会社エヌオーアイ NIO Co., Ltd.	passive	429.4K	¥1,212	-	¥520M ($3.4M)
2025-06-06	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	533.9K	¥1,212	-	-
2025-04-30	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	533.9K	¥1,215	-	-
2025-04-30	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	61.6K	¥1,215	-	-
2025-04-30	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,215	-	-
2025-04-30	BUY	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.7M	¥1,215	-	-
2025-04-03	SELL	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	533.9K	¥1,183	+3.3%	¥1.2B ($7.6M)
2025-04-03	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,183	-	-
2025-04-03	BUY	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.7M	¥1,183	-	-
2025-04-03	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	61.6K	¥1,183	-	-
2025-03-11	SELL	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	1.5M	¥1,220	+6.2%	¥236M ($1.5M)
2025-03-11	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,220	-6.2%	¥145M ($933K)
2025-03-11	SELL	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.7M	¥1,220	+6.2%	¥15M ($98K)
2025-03-11	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	61.6K	¥1,220	-	¥75M ($485K)
2021-09-14	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	1.2M	¥686.67	+66.6%	¥536M ($3.5M)
2021-09-14	BUY	Market Buy	株式会社UH Partners 3 UH Partners 3 Co., Ltd.	passive	1.1M	¥686.67	-	¥790M ($5.1M)
2021-09-14	SELL	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	unknown	0	¥686.67	-66.6%	¥1.8B ($11.7M)
2021-09-14	SELL	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	764.3K	¥686.67	-66.6%	¥523M ($3.4M)
2021-08-31	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	2.6M	¥638.67	-	-
2021-08-31	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	370.2K	¥638.67	+79.1%	¥79M ($508K)
2021-08-31	BUY	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	15.0K	¥638.67	-	¥10M ($62K)
2021-08-13	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	2.6M	¥638.67	-	-
2021-08-13	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	246.5K	¥638.67	+79.1%	¥93M ($600K)

Frequently asked questions

Who has been buying Toho System Science Co., Ltd. stock?: 6 distinct investors have filed 4 disclosed large-shareholding filings in Toho System Science Co., Ltd. (4333), most recently on 2025-09-26. 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 Toho System Science Co., Ltd. have?: Toho System Science Co., Ltd. has 4 buy-side and 6 sell-side disclosures on record, covering ¥852M ($5.5M) in total reported value, spanning 2021-08-13 to 2025-09-26.
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.