Seigo Naito内藤 征吾

Major shareholder of Optimus Group Company Limited

Net worth (est.)
¥23.3B
#240 in Japan
Listed shares ¥20.2B + other assets ¥3.1B
Executive pay
—
Not disclosed
Dividends (a year)
¥722M
#136
Total income (est.)
¥722M
#172
Pay + dividends, before tax
Taxes (est.)
¥147M
#345
Income tax ¥111M / resident tax ¥36.1M
Other assets (est.)
¥3.1B
After-tax income 2016–2026 (incl. ¥1.5B from share sales), before spending
Inheritance tax (est.)
¥6.3B
#227
If a spouse and two children inherit in statutory shares (change)

Other assets (est.): the sum of each year's after-tax income (pay + dividends in own name − estimated taxes and social insurance) dividends retained by asset-management companies (less about 20% corporate tax), and proceeds from share sales (the drop in shares from the previous year × share price, less 20.315% tax, or about 30% for asset-management companies), for the years we have data. Spending, real estate, donations and savings from earlier years are not reflected.

Holdings

CompanyHeld bySharesStakePriceValueDividends
Optimus Group Company Limited
9268 · FY ending Mar 2026
Own name 2,287,200 3.34% ¥1,092 ¥2.5B ¥41.2M
The Zenitaka Corporation
1811 · FY ending Mar 2026
Own name 151,000 2.11% ¥8,257 ¥1.2B ¥18.1M
Nippi,Incorporated
7932 · FY ending Mar 2026
Own name 85,000 3.04% ¥12,120 ¥1.0B ¥59.2M
Parker Corporation
9845 · FY ending Mar 2026
Own name 635,000 2.50% ¥1,386 ¥880M ¥33.7M
Seikagaku Corporation
4548 · FY ending Mar 2026
Own name 1,141,000 2.09% ¥729 ¥831M ¥34.2M
NISSHIN GROUP HOLDINGS Co., Ltd.
8881 · FY ending Mar 2026
Own name 1,158,600 2.47% ¥706 ¥818M ¥40.6M
GREE Holdings, Inc.
3632 · FY ending Jun 2026
Own name 1,851,000 1.03% ¥376 ¥696M ¥40.7M
Musashi Co.,Ltd.
7521 · FY ending Mar 2026
Own name 228,000 3.35% ¥2,715 ¥619M ¥17.3M
Sanyo Engineering & Construction Inc.
1960 · FY ending Mar 2026
Own name 463,000 3.02% ¥1,315 ¥609M ¥30.1M
First Juken Co.,Ltd.
8917 · FY ending Oct 2025
Own name 506,000 3.64% ¥1,114 ¥564M ¥21.8M
株式会社デジタルホールディングス
2389 · FY ending Dec 2024
Own name 452,000 2.58% ¥1,217 ¥550M ¥29.4M
Ku Holdings Co.,Ltd.
9856 · FY ending Mar 2026
Own name 459,000 1.47% ¥1,176 ¥540M ¥26.6M
Yoshicon Co.,Ltd
5280 · FY ending Mar 2026
Own name 186,000 2.67% ¥2,379 ¥442M ¥15.8M
Kawagishi Bridge Works Co.,Ltd.
5921 · FY ending Sep 2025
Own name 89,000 3.28% ¥4,585 ¥408M ¥14.2M
Watanabe Sato Co., Ltd.
1807 · FY ending Mar 2026
Own name 190,000 3.05% ¥1,996 ¥379M ¥15.2M
IR Japan Holdings, Ltd.
6035 · FY ending Mar 2026
Own name 521,900 2.93% ¥703 ¥367M ¥14.6M
Wesco Holdings Inc.
6091 · FY ending Jul 2026
Own name 383,000 2.95% ¥869 ¥333M ¥11.5M
Imagineer Co.,Ltd.
4644 · FY ending Mar 2026
Own name 319,000 3.30% ¥1,014 ¥324M ¥19.1M
Biken Techno Corporation
9791 · FY ending Mar 2026
Own name 231,000 3.06% ¥1,400 ¥323M ¥8.3M
Mikikogyo Co.,Ltd.
1718 · FY ending Dec 2025
Own name 34,200 3.12% ¥8,614 ¥295M ¥12.0M
Endo Manufacturing Co.,Ltd.
7841 · FY ending Dec 2025
Own name 246,000 2.80% ¥1,184 ¥291M ¥9.8M
WILLPLUS Holdings Corporation
3538 · FY ending Jun 2026
Own name 309,500 3.16% ¥890 ¥275M ¥14.2M
Applied Co., Ltd.
3020 · FY ending Mar 2026
Own name 67,200 2.49% ¥3,777 ¥254M ¥8.7M
KOMAIHALTEC Inc.
5915 · FY ending Mar 2026
Own name 130,300 2.80% ¥1,942 ¥253M ¥9.1M
Zenken Corporation
7371 · FY ending Jun 2026
Own name 333,152 2.73% ¥705 ¥235M ¥9.0M
Nichiwa Sangyo Co., Ltd.
2055 · FY ending Mar 2026
Own name 601,000 3.32% ¥384 ¥231M ¥3.6M
First Brothers Co., Ltd.
3454 · FY ending Nov 2025
Own name 196,200 1.40% ¥1,169 ¥229M ¥6.9M
Tanaka Co.,Ltd
7619 · FY ending Mar 2026
Own name 260,000 3.20% ¥853 ¥222M ¥8.1M
i.a groupcorporation
7509 · FY ending Mar 2026
Own name 48,700 3.30% ¥4,468 ¥218M ¥7.3M
TAKADAKIKO(Steel Construction)CO.,LTD.
5923 · FY ending Mar 2026
Own name 200,000 3.43% ¥1,022 ¥204M ¥10.0M
Fuji Seiko Limited
6142 · FY ending Feb 2026
Own name 129,000 4.04% ¥1,547 ¥200M ¥1.9M
株式会社アイ・オー・データ機器
6916 · FY ending Jun 2021
Own name 187,000 1.45% ¥1,030 ¥193M ¥4.7M
Denkyo Group Holdings Co.,Ltd.
8144 · FY ending Mar 2026
Own name 140,000 2.23% ¥1,337 ¥187M ¥6.0M
HONYAKU Center Inc.
2483 · FY ending Mar 2026
Own name 100,000 2.97% ¥1,805 ¥180M ¥14.0M
Justplanning Inc.
4287 · FY ending Jan 2026
Own name 365,200 3.12% ¥469 ¥171M ¥4.0M
Kobayashi Yoko Co.,Ltd.
8742 · FY ending Mar 2026
Own name 353,000 2.95% ¥455 ¥161M ¥2.1M
Takamisawa Co., Ltd.
5283 · FY ending Jun 2026
Own name 52,000 3.18% ¥2,908 ¥151M ¥3.6M
株式会社メルディアDC
1739 · FY ending Jun 2023
Own name 193,300 3.18% ¥780 ¥151M ¥3.3M
C.S. Lumber Co., Inc
7808 · FY ending May 2026
Own name 55,200 2.99% ¥2,660 ¥147M ¥4.4M
株式会社イボキン
5699 · FY ending Dec 2025
Own name 101,000 3.09% ¥1,413 ¥143M ¥3.2M
The Kosei Securities Co.,Ltd
8617 · FY ending Mar 2026
Own name 281,000 2.98% ¥504 ¥142M ¥2.8M
Apple Internationalco.,Ltd.
2788 · FY ending Dec 2025
Own name 414,800 3.20% ¥337 ¥140M ¥4.1M
Gendai Agency Inc.
2411 · FY ending Mar 2026
Own name 286,300 2.60% ¥460 ¥132M ¥6.9M
Taiyo Kisokogyo Co.,Ltd.
1758 · FY ending Jan 2026
Own name 51,000 2.57% ¥2,554 ¥130M ¥3.1M
Shinden Hightex Corporation
3131 · FY ending Mar 2026
Own name 48,300 2.56% ¥2,614 ¥126M ¥6.3M
Maruhachi Holdings Co., Ltd.
3504 · FY ending Mar 2026
Own name 111,000 0.72% ¥1,124 ¥125M ¥5.5M
IID, Inc.
6038 · FY ending Jun 2026
Own name 150,000 3.05% ¥801 ¥120M ¥3.5M
株式会社ファミリー
8298 · FY ending Mar 2021
Own name 191,000 3.42% ¥611 ¥117M ¥1.9M
Asmo Corporation
2654 · FY ending Mar 2026
Own name 292,000 2.17% ¥397 ¥116M ¥2.9M
Harima-Kyowa Co.,LTD.
7444 · FY ending Mar 2026
Own name 58,000 1.08% ¥1,996 ¥116M ¥3.5M
ヤマシタヘルスケアホールディングス株式会社
9265 · FY ending May 2026
Own name 37,100 1.46% ¥3,077 ¥114M ¥4.0M
株式会社クレステック
7812 · FY ending Jun 2026
Own name 53,100 1.75% ¥2,137 ¥113M ¥5.5M
株式会社一六堂
3366 · FY ending Feb 2018
Own name 188,700 1.95% ¥459 ¥86.6M ¥1.9M
Medical Net , Inc.
3645 · FY ending May 2026
Own name 322,400 3.48% ¥265 ¥85.4M ¥967,200
Chuokeizai-Sha Holdings,Inc.
9476 · FY ending Sep 2025
Own name 116,000 2.65% ¥716 ¥83.0M ¥1.5M
Ykt Corporation
2693 · FY ending Dec 2025
Own name 354,000 3.06% ¥228 ¥80.7M ¥1.8M
EARLY AGE CO., Ltd.
3248 · FY ending Oct 2025
Own name 94,700 2.98% ¥837 ¥79.2M ¥3.4M
Moriya Corporation
1798 · FY ending Mar 2026
Own name 65,000 2.98% ¥1,196 ¥77.7M ¥11.7M
Saita Corporation
1999 · FY ending Jun 2026
Own name 19,000 3.12% ¥4,057 ¥77.1M ¥1.3M
Zoa Corporation
3375 · FY ending Mar 2026
Own name 43,000 3.42% ¥1,778 ¥76.5M ¥3.2M
Nansin Co., Ltd.
7399 · FY ending Mar 2026
Own name 130,000 1.96% ¥585 ¥76.0M ¥2.6M
株式会社インテリックス
8940 · FY ending May 2025
Own name 71,626 0.88% ¥888 ¥63.6M ¥3.3M
Innovation Inc.
3970 · FY ending Mar 2026
Own name 55,500 2.01% ¥1,120 ¥62.2M ¥2.2M
INTELLEX HOLDINGS Co.,Ltd.
463A · FY ending May 2026
Own name 67,500 0.68% ¥904 ¥61.1M ¥1.6M
Jss Corporation
6074 · FY ending Mar 2026
Own name 120,000 2.98% ¥508 ¥60.9M ¥2.4M
Nittoh Corporation
1738 · FY ending Mar 2026
Own name 87,000 2.16% ¥613 ¥53.4M ¥1.6M
株式会社ボルテージ
3639 · FY ending Jun 2026
Own name 189,300 2.91% ¥264 ¥49.9M —
Sonocom Co.,Ltd.
7902 · FY ending Mar 2026
Own name 46,000 1.26% ¥1,057 ¥48.6M ¥598,000
NIHON ISK Company, Limited
7986 · FY ending Dec 2025
Own name 26,000 1.70% ¥1,792 ¥46.6M ¥780,000
Casa Inc.
7196 · FY ending Jan 2026
Own name 58,900 0.65% ¥713 ¥42.0M ¥883,500
TAC株式会社
4319 · FY ending Mar 2025
Own name 203,400 1.12% ¥204 ¥41.4M ¥813,600
Truck-One Co., Ltd.
3047 · FY ending Dec 2025
Own name 72,200 3.01% ¥505 ¥36.4M ¥794,200
Global-Dining,Inc.
7625 · FY ending Dec 2025
Own name 81,000 0.78% ¥405 ¥32.8M ¥405,000
株式会社ザッパラス
3770 · FY ending Apr 2025
Own name 75,900 0.85% ¥404 ¥30.7M ¥379,500
Kowa Co.,Ltd.
7807 · FY ending Feb 2026
Own name 31,000 0.76% ¥855 ¥26.5M ¥403,000
株式会社トラスト
3347 · FY ending Mar 2025
Own name 85,400 0.33% ¥287 ¥24.5M ¥512,400
Kitalive Inc.
5039 · FY ending Dec 2025
Own name 12,600 1.00% ¥1,450 ¥18.3M —
Laxus Technologies Inc.
288A · FY ending Mar 2026
Own name 144,500 0.56% ¥117 ¥16.9M —
WellcoHoldings Corporation
7831 · FY ending Oct 2025
Own name 321,000 2.06% — — ¥642,000

By year

YearNet worthListed sharesPayDividendsTotal incomeTaxes (est.)After tax (est.)Share sales (after tax)
2026partial¥22.8B¥19.7B—¥606M¥606M¥123M¥483M¥399M
2025partial¥15.5B¥13.3B—¥477M¥477M¥96.9M¥380M¥116M
2024partial¥10.6B¥8.9B—¥294M¥294M¥59.7M¥234M¥197M
2023¥7.3B¥6.0B—¥213M¥213M¥43.4M¥170M¥148M
2022partial¥5.2B¥4.2B—¥121M¥121M¥24.6M¥96.4M¥5.3M
2021¥4.7B¥3.9B—¥104M¥104M¥21.1M¥82.9M¥25.2M
2020¥3.3B¥2.5B—¥77.6M¥77.6M¥15.8M¥61.9M¥120M
2019partial¥3.1B¥2.5B—¥63.4M¥63.4M¥12.9M¥50.5M¥25.4M
2018¥2.3B¥1.8B—¥38.8M¥38.8M¥7.9M¥30.9M¥148M
2017¥1.8B¥1.5B—¥28.7M¥28.7M¥5.0M¥23.6M¥302M
2016¥587M¥579M—¥9.3M¥9.3M¥1.9M¥7.4M—

"Partial" years carry forward the previous year's value for companies that have not yet filed that year's annual report (such as December year-end companies). Pay and dividends cover only companies that have filed.

Net worth for each year is listed shares plus the other assets (est.) accumulated up to that year. Grouped by the calendar year of each company's fiscal year-end. Years in which the person was not among the top 10 shareholders of a company exclude that company.

Inheritance tax (estimate)

Estate ¥23.3B = listed shares in own name ¥20.2B + other assets (est.) ¥3.1B

Total inheritance tax paid: ¥6.3B (27.0% of the estate).

HeirInheritsTaxAfter tax
Spouse¥11.7B¥0¥11.7B
Each child¥5.8B¥3.1B¥2.7B

Japanese inheritance tax, assuming the estate is split in statutory shares. A spouse pays no tax up to ¥160M or the statutory share, whichever is larger. Family size is not in the securities reports, so you can choose it (with no children, parents or siblings also become heirs, so the real figure differs). Business-succession deferrals, lifetime gifts, donations to foundations, debts and other reliefs are not reflected.

Estimates from annual securities reports (EDINET). The English name is romanized automatically and may differ from the spelling the person uses. Methodology · Corrections and removal requests: contact