The Ideal Marriage I Choose

Haruh Idenaguchi, 34, has been in a long-term, comfortable relationship with her boyfriend, Naotaka. Though stable, the romance has gone cold and excitement has faded—something she tries to justify as normal. Everything changes when she sees him walking with a younger woman, smiling at her the way he used to smile at Haruh. Her everyday life begins to crumble when Mamiya, her ideal man, appears before her. What she truly desires: comfort? passion? or something more?
https://www.cmoa.jp/title/327619/