マー君のばあちゃん

Masa's grandmother.

In Yutaro Segawa's younger years, he attempts to scam her as part of a scheme to get money and pay off his debts to Takarada Financing. She mistakes Segawa for her grandson, Masa, and his inability to scam her leads to Segawa being roped into the Tenryu-gumi and work under Asao Ozu to pay off his debts.