Who has been buying Koyosha Inc. stock?

17 distinct investors have filed 22 disclosed large-shareholding filings in Koyosha Inc. (7946), most recently on 2025-04-18. 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 Koyosha Inc. have?

Koyosha Inc. has 22 buy-side and 4 sell-side disclosures on record, covering ¥198M ($1.3M) in total reported value, spanning 2021-03-22 to 2025-04-18.

Where does StockDrifts get Koyosha Inc. 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.

Koyosha Inc. 7946

Company

株式会社光陽社Koyosha Inc.

Investors

Buys

Total Value

¥198M ($1.3M)

Avg Return

+31.12%

Last Filing

2025-04-18

Koyosha Inc. (7946) has 22 disclosed large-shareholding filings and 4 disclosed disposals on record, filed by 17 distinct investors. Together those filings cover ¥198M ($1.3M) in reported transaction value. The earliest filing StockDrifts holds for Koyosha Inc. is dated 2021-03-22; the most recent is 2025-04-18. 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 +31.12%, 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
2025-04-18	BUY	unknown	株式会社KK KK Co., Ltd.	activist	50.0K	¥272	+49.6%	¥2M ($13K)
2025-04-18	BUY	Market Buy	株式会社KK KK Co., Ltd.	activist	50.0K	¥272	+49.6%	¥2M ($13K)
2025-04-18	BUY	Market Buy	犬養岬太 KOTA INUKAI	activist	144.7K	¥272	+49.6%	¥6M ($38K)
2025-04-18	BUY	unknown	犬養岬太 KOTA INUKAI	activist	144.7K	¥272	+49.6%	¥6M ($38K)
2025-03-28	BUY	unknown	学校法人日吉台学園 HIYOSHIDAIGAKUEN	other	0	¥293.6	+38.6%	¥42M ($271K)
2025-03-28	BUY	unknown	学校法人日吉台学園 Hiyoshidaigakuen	other	150.0K	¥293.6	+38.6%	¥44M ($284K)
2025-03-28	BUY	unknown	学校法人日吉台学園 Hiyoshidaigakuen	other	150.0K	¥293.6	+38.6%	¥44M ($284K)
2025-03-28	SELL	unknown	学校法人日吉台学園 HIYOSHIDAIGAKUEN	other	0	¥293.6	-38.6%	-
2025-03-03	BUY	Market Buy	株式会社KK KK Co., Ltd.	activist	50.0K	¥296	+37.5%	¥15M ($95K)
2025-03-03	BUY	Market Buy	犬養岬太 KOTA INUKAI	activist	144.7K	¥296	+37.5%	¥12M ($79K)
2022-04-25	BUY	unknown	犬養岬太 KOTA INUKAI	activist	144.7K	¥232.6	+75.0%	¥34M ($217K)
2022-04-11	SELL	unknown	植島幹九郎 Kankuro Ueshima	unknown	0	¥249.2	-63.3%	¥106M ($686K)
2022-04-11	BUY	unknown	植島幹九郎 Kankuro Ueshima	unknown	0	¥249.2	+63.3%	¥106M ($686K)
2022-03-11	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	426.9K	¥238.6	+70.6%	¥102M ($657K)
2021-12-13	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	426.9K	¥294.4	+38.3%	¥4M ($23K)
2021-10-20	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	414.6K	¥524	-22.3%	¥13M ($86K)
2021-10-07	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	389.1K	¥338	+20.4%	¥10M ($64K)
2021-10-07	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	389.1K	¥338	+20.4%	¥10M ($64K)
2021-09-16	BUY	unknown	千葉達也 Tatsuya Chiba	strategic	2.5K	¥303.6	+34.1%	¥759K ($5K)
2021-09-16	BUY	unknown	住井秀行 Hideyuki Sumii	strategic	1.1K	¥303.6	+34.1%	¥334K ($2K)
2021-09-16	BUY	unknown	冨正俊 Masatoshi Tomi	activist	6.8K	¥303.6	+34.1%	¥2M ($13K)
2021-09-16	BUY	unknown	木曽茂樹 Shigeki Kiso	strategic	1.0K	¥303.6	+34.1%	¥304K ($2K)
2021-09-16	BUY	unknown	株式会社尾上紙店 Onoe Paper Co., Ltd.	strategic	8.7K	¥303.6	+34.1%	¥3M ($17K)
2021-09-16	BUY	unknown	株式会社研文社 Kenbunsha Co., Ltd.	strategic	8.9K	¥303.6	+34.1%	¥3M ($17K)
2021-09-16	BUY	unknown	株式会社片山 Katayama Co., Ltd.	strategic	61.4K	¥303.6	+34.1%	¥19M ($120K)
2021-09-16	BUY	unknown	株式会社石川商会 Ishikawa Shokai Co., Ltd.	strategic	17.5K	¥303.6	+34.1%	¥5M ($34K)
2021-09-16	BUY	unknown	新日本カレンダー株式会社 New Japan Calendar Co., Ltd.	strategic	50.0K	¥303.6	+34.1%	¥15M ($98K)
2021-09-16	BUY	unknown	片山英彦 Hidehiko Katayama	strategic	15.5K	¥303.6	+34.1%	¥5M ($30K)
2021-09-16	BUY	unknown	サカタインクス株式会社 Sakata INX Corporation	strategic	6.6K	¥303.6	+34.1%	¥2M ($13K)
2021-09-16	BUY	unknown	学校法人日吉台学園 HIYOSHIDAIGAKUEN	other	200.0K	¥303.6	+34.1%	¥61M ($392K)
2021-09-16	BUY	unknown	犬養岬太 KOTA INUKAI	activist	144.7K	¥303.6	+34.1%	¥44M ($283K)
2021-09-03	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	359.5K	¥310.2	+31.2%	¥3M ($18K)
2021-07-01	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	350.4K	¥279.8	+45.5%	¥7M ($44K)
2021-06-24	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	325.8K	¥317	+28.4%	¥6M ($37K)
2021-06-22	BUY	unknown	犬養岬太 KOTA INUKAI	activist	144.7K	¥268	+51.9%	¥39M ($250K)
2021-06-22	SELL	Market Buy	サイブリッジ合同会社 CYBRiDGE LLC	activist	0	¥268	-51.9%	¥26M ($169K)
2021-06-22	SELL	Market Buy	水口翼 Tsubasa Mizuguchi	activist	0	¥268	-51.9%	¥19M ($121K)
2021-05-10	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	307.9K	¥224	+81.7%	¥4M ($28K)
2021-04-27	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	288.9K	¥236.4	+72.2%	¥5M ($35K)
2021-04-26	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	266.2K	¥220.4	+84.7%	¥16M ($102K)
2021-04-23	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	194.8K	¥219.8	+85.2%	¥8M ($55K)
2021-04-22	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	156.2K	¥219.2	+85.7%	¥4M ($28K)
2021-04-22	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	156.2K	¥219.2	+85.7%	¥4M ($28K)
2021-04-20	BUY	Market Buy	植島幹九郎 Kankuro Ueshima	activist	136.4K	¥231	+76.2%	¥32M ($203K)
2021-04-19	BUY	Market Buy	水口翼 Tsubasa Mizuguchi	activist	70.1K	¥216.4	+88.1%	¥15M ($98K)
2021-04-19	BUY	Market Buy	サイブリッジ合同会社 CYBRiDGE LLC	activist	1.0K	¥216.4	+88.1%	¥216K ($1K)
2021-03-22	BUY	Market Buy	水口翼 Tsubasa Mizuguchi	activist	70.1K	¥959.057	-57.6%	¥67M ($434K)
2021-03-22	BUY	Market Buy	水口翼 Tsubasa Mizuguchi	activist	71.1K	¥959.057	-57.6%	¥68M ($440K)
2021-03-22	BUY	Market Buy	サイブリッジ合同会社 CYBRiDGE LLC	activist	1.0K	¥959.057	-57.6%	¥959K ($6K)
2021-03-22	BUY	Market Buy	サイブリッジ合同会社 CYBRiDGE LLC	activist	1.0K	¥959.057	-57.6%	¥959K ($6K)

Frequently asked questions

Who has been buying Koyosha Inc. stock?: 17 distinct investors have filed 22 disclosed large-shareholding filings in Koyosha Inc. (7946), most recently on 2025-04-18. 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 Koyosha Inc. have?: Koyosha Inc. has 22 buy-side and 4 sell-side disclosures on record, covering ¥198M ($1.3M) in total reported value, spanning 2021-03-22 to 2025-04-18.
Where does StockDrifts get Koyosha Inc. 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 Koyosha Inc.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.