[adventured]

By a large margin over Masayoshi Son, the richest in Japan title now goes to Tadashi Yanai of Fast Retailing:

https://www.bloomberg.com/billionaires/profiles/tadashi-yana...

After that is Takemitsu Takizaki, of Keyence:

https://www.bloomberg.com/billionaires/profiles/takemitsu-ta...