AICHI (TR) – Former professional boxing world champion and popular television personality Yasuei Yakushiji and his 29-year-old mistress appeared in the Nagoya District Court on August 5, where prosecutors sought a one-year prison sentence over forged adoption documents, reports News Post Seven (Aug. 15).
Both Yakushiji, 58, and Shihori, a former model who works as a receptionist at his boxing gym, pleaded guilty to charges of forging and using a private document. The charges stem from a scheme to legally adopt the younger woman without the consent of Yakushiji’s estranged wife.
According to prosecutors, the pair began an extramarital affair shortly after Yakushiji married his current wife in 2015. By 2022, Yakushiji and his wife had separated over financial disagreements, and he subsequently moved in with Shihori.
“Never divorce him”
Despite Yakushiji’s strong desire to formally split, his wife reportedly vowed through acquaintances that she would “never divorce him even if she dies,” causing negotiations to stall.
Desperate to give Shihori the “Yakushiji” family name to appease her elderly grandparents, the former boxing champion initially had his own parents adopt her — briefly making his mistress his legal younger sister.
However, less than a month later, motivated by a desire to ensure Shihori would inherit his assets, the pair escalated their plan. Prosecutors stated that Shihori fraudulently signed the estranged wife’s name in the “adoptive mother” section of a municipal adoption form. The documents were submitted to the local ward office, officially registering the mistress as the couple’s adopted daughter.
“Severe punishment”
The plot unraveled when the estranged wife heard rumors from an acquaintance that Shihori was openly using the Yakushiji surname. Suspicious, she obtained a copy of the family register and discovered the fraudulent adoption.
During the police investigation, the wife demanded that the pair face “severe punishment.”
Appearing in court in a suit that highlighted his thick, athletic build, Yakushiji identified himself as a “company executive” and answered questions directly. He testified that sometime after the forgery was committed, he received sudden notification from the city hall that his divorce had finally been finalized — rendering the criminal lengths he went to for his inheritance plans ultimately pointless.
The court is expected to hand down its ruling at a later date.
