MIAA-365 My new girlfriend ended up being the little sister of that playboy senior... Mitsu Hagikuchi.

Mitsu was living happy days with her kind boyfriend, but then her parents' remarriage brought an older half-brother into her life... and he turned out to be the notorious playboy senior at her boyfriend's part-time job. On a day when her parents were away, she was attacked and impregnated, shattering her happy routine. Under the same roof, her vagina was gradually remodeled for her brother-in-law's use. She increasingly stopped answering her boyfriend's calls, eagerly offering blowjobs. She transformed into an orgasm-loving sex girl, unable to live without her brother-in-law...