Who has been buying Nihon Office Automation Research Co., Ltd. stock?

6 distinct investors have filed 12 disclosed large-shareholding filings in Nihon Office Automation Research Co., Ltd. (5241), most recently on 2026-04-08. 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 Nihon Office Automation Research Co., Ltd. have?

Nihon Office Automation Research Co., Ltd. has 12 buy-side and 1 sell-side disclosures on record, covering ¥325M ($2.1M) in total reported value, spanning 2024-12-25 to 2026-04-08.

Where does StockDrifts get Nihon Office Automation Research Co., Ltd. insider data?

From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.

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.

Nihon Office Automation Research Co., Ltd. 5241

Company

株式会社日本オーエー研究所Nihon Office Automation Research Co., Ltd.

Investors

Buys

Total Value

¥325M ($2.1M)

Avg Return

+1.24%

Last Filing

2026-04-08

Nihon Office Automation Research Co., Ltd. (5241) has 12 disclosed large-shareholding filings and 1 disclosed disposals on record, filed by 6 distinct investors. Together those filings cover ¥325M ($2.1M) in reported transaction value. The earliest filing StockDrifts holds for Nihon Office Automation Research Co., Ltd. is dated 2024-12-25; the most recent is 2026-04-08. All of it is parsed from EDINET large-shareholding (5%+) reports, the official disclosure system operated by the Financial Services Agency (Japan). Across these filings the average return since disclosure is +1.24%, 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
2026-08-07	BUY	Market Buy	株式会社UH6	passive	12.0K	¥500	+0.0%	¥6M ($39K)
2026-08-07	BUY	Market Buy	株式会社UH Partners 2	passive	65.3K	¥500	+0.0%	¥8M ($53K)
2026-08-07	BUY	Market Buy	光通信株式会社	passive	121.6K	¥500	+0.0%	¥61M ($392K)
2026-06-24	BUY	unknown	奥山宏昭 HIROAKI OKUYAMA	other	817.4K	¥500	+0.0%	¥55M ($355K)
2026-06-24	BUY	unknown	奥山宏昭 HIROAKI OKUYAMA	other	817.4K	¥500	+0.0%	¥55M ($355K)
2026-04-08	BUY	Market Buy	株式会社UH Partners 2	passive	48.8K	¥500	+0.0%	¥8M ($52K)
2026-04-08	BUY	Market Buy	光通信株式会社	passive	121.6K	¥500	+0.0%	¥61M ($392K)
2026-04-08	BUY	Market Buy	株式会社UH6	passive	12.0K	¥500	+0.0%	¥6M ($39K)
2026-04-08	SELL	Market Buy	株式会社UH5	unknown	0	¥500	+0.0%	¥6M ($39K)
2026-02-02	BUY	Market Buy	株式会社UH5	passive	12.0K	¥500	+0.0%	¥6M ($39K)
2026-02-02	BUY	Market Buy	株式会社UH Partners 2	passive	32.6K	¥500	+0.0%	¥16M ($105K)
2026-02-02	BUY	Market Buy	光通信株式会社	passive	121.6K	¥500	+0.0%	¥61M ($392K)
2025-12-16	BUY	Market Buy	株式会社UH5	passive	6.0K	¥500	+0.0%	¥3M ($19K)
2025-12-16	BUY	Market Buy	株式会社UH Partners 2	passive	8.1K	¥500	+0.0%	¥4M ($26K)
2025-12-16	BUY	Market Buy	光通信株式会社	passive	60.8K	¥500	+0.0%	¥30M ($196K)
2025-11-13	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	60.8K	¥500	+0.0%	¥4M ($26K)
2025-11-13	BUY	Market Buy	株式会社UH5 UH5 Co., Ltd.	passive	6.0K	¥500	+0.0%	¥3M ($19K)
2025-10-27	BUY	Market Buy	株式会社UH5 UH5 Co., Ltd.	passive	6.0K	¥500	+0.0%	¥2M ($15K)
2025-10-27	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	52.6K	¥500	+0.0%	¥2M ($12K)
2025-09-29	BUY	Market Buy	株式会社UH5 UH5 Co., Ltd.	passive	1.3K	¥500	+0.0%	¥643K ($4K)
2025-09-29	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	49.0K	¥500	+0.0%	¥3M ($22K)
2025-09-02	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	42.2K	¥500	+0.0%	¥21M ($136K)
2024-12-25	BUY	Market Buy	奥山伸子 NOBUKO OKUYAMA	passive	98.0K	¥482	+3.7%	¥47M ($305K)
2024-12-25	BUY	Market Buy	奥山伸子 NOBUKO OKUYAMA	passive	98.0K	¥482	+3.7%	¥47M ($305K)
2024-12-25	BUY	negotiated	奥山宏昭 HIROAKI OKUYAMA	activist	463.7K	¥482	+3.7%	¥224M ($1.4M)
2024-12-25	BUY	negotiated	奥山宏昭 HIROAKI OKUYAMA	activist	463.7K	¥482	+3.7%	¥224M ($1.4M)
2024-12-25	BUY	unknown	奥山宏昭 HIROAKI OKUYAMA	activist	463.7K	¥482	+3.7%	¥224M ($1.4M)
2024-12-25	BUY	Market Buy	奥山伸子 NOBUKO OKUYAMA	passive	98.0K	¥482	+3.7%	¥47M ($305K)

Frequently asked questions

Who has been buying Nihon Office Automation Research Co., Ltd. stock?: 6 distinct investors have filed 12 disclosed large-shareholding filings in Nihon Office Automation Research Co., Ltd. (5241), most recently on 2026-04-08. 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 Nihon Office Automation Research Co., Ltd. have?: Nihon Office Automation Research Co., Ltd. has 12 buy-side and 1 sell-side disclosures on record, covering ¥325M ($2.1M) in total reported value, spanning 2024-12-25 to 2026-04-08.
Where does StockDrifts get Nihon Office Automation Research Co., Ltd. insider data?: From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.
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.

Source filings

Every trade listed above is disclosed in EDINET large-shareholding (5%+) reports, filed with the Financial Services Agency (Japan). View the original EDINET filings for Nihon Office Automation Research Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.