Shares of Trial Holdings surged 32% in the past 12 months, boosting the net worth of chairman Hisao Nagata to $1.4 billion.

© Trial Holdings

SoftBank’s Masayoshi Son powers up with a multibillion dollar bet on OpenAI to reclaim the top spot.

© Getty

Shares of Open House jumped 38% in the past 12 months, boosting Arai’s net worth by $400 million to $2.4 billion.

© Open House Group

The family behind oil refining giant Idemitsu Kosan, represented by board member Masakazu Idemitsu, is one of five new entries on the list.

© Idemitsu Kosan Co.,Ltd

After a four year gap, billionaire Masayoshi Son reclaims the title of Japan’s richest person as his SoftBank Group’s shares more than tripled, boosting his net worth to a record $80 billion.

© Andrew Harnik/Getty Images