Your Party member Kota Matsuda, with ¥486.45 million in assets, is the wealthiest of the 121 Upper House members who won in July, according to a tally based on their financial reports released Tuesday.

Matsuda, founder of coffee chain operator Tully's Coffee Japan Co., won a Diet seat for the first time in the July 11 election. He was followed in wealth by Akio Koizumi of the Liberal Democratic Party at ¥294.85 million and Your Party's Kenji Nakanishi at ¥258.78 million.

Assets held by the 121 Upper House members averaged ¥30.67 million, up 29.0 percent from January 2008, when the remaining members of the chamber disclosed their assets in line with the law after winning their seats in the 2007 election.