Domestic na Kanojo

研究正文明确给出占据主线的男性恋爱对象、异性恋主线或男性中心后宫结构。 The central structure is a male/female love triangle involving Natsuo, Hina, and Rui. No central female/female romance is established. 剧情依据：High-schooler Natsuo is in love with teacher Hina, has sex with Rui, and then learns both women will become his stepsisters after their parents marry. 结局范围：The anime adaptation does not cover the complete manga resolution; final relationship outcome is not established by the reviewed anime source. 男性关系：male protagonist with two female central romantic/sexual interests confirmed 关系背叛：love-triangle and overlapping attractions are central; exact NTR classification and timing require detailed review 亲密内容：sexual relationship/one-night encounter is part of the premise 参与者：male high-school student and female peer; teacher/student romantic interest also central 年龄与同意：high-school sexual content and teacher/student power differential require age/consent review 强迫与控制：no coercion established in reviewed synopsis, but power imbalance is present 暴力与恐怖：not central in reviewed premise 待补证：Verify detailed ending and any later-volume relationship changes not covered by the reviewed sources. 基于既有研究资料作出的 AI 评级；未重新抓取外部资料。未知项不表示安全或不存在。