Kagemasa Kozuki. This story is part of Forbes’ coverage of Japan’s Richest 2025. See the full list here. Gaming billionaire Kagemasa Kozuki, whose Konami Group scored a twofer with its esports game series and a horror media franchise, is the biggest gainer in percentage terms this year. Thanks to these hits, Kozuki’s net worth doubled to $3.5 billion from a year ago as shares of the Tokyo-listed company soared. Konami’s eFootball game, which has notched over 850 million downloads worldwide since its release in 2021, “is driving the profits of the digital entertainment business,” Japan Credit Rating Agency noted in an April report. Earlier this year, Konami added Spanish soccer player Lamine Yamal to its lineup of brand ambassadors that includes Argentinian soccer star Lionel Messi. The company also got a jolt from “Silent Hill 2,” a remake of the horror game classic it published 24 years ago, which has sold over two million copies since its release in October. Konami’s revenue jumped 17% to ¥421.6 billion ($2.9 billion) in the year ended March, while net profit surged 26% to ¥74.7 billion. Kozuki started Konami as a jukebox rental and repair shop in Osaka in 1969; in addition to online, video, card and arcade games, Konami today sells gaming machines and casino-management systems and operates Konami Sports Club, one of the largest fitness club brands in Japan. Editorial StandardsReprints & Permissions