Onii-chan wa Oshimai!

按本作已核实的具体关系或设定事实应用现行评级类别。 This is an explicit male-to-female bodily transformation/gender-bender premise. It does not by itself establish transgender identity or an original female-female romance. 剧情依据：Adult male shut-in Mahiro is transformed into a female body by his younger sister’s experiment and learns to live socially as a girl while attempting to leave isolation. 结局范围：The licensed manga series is ongoing, so no final transformation, identity, or relationship ending is available. 男性关系：mahiro_is_explicitly_a_male_before_being_changed_into_a_female_body 关系背叛：no_ntr_fact_established 亲密内容：erotic-game references and body-change comedy are explicit; exact nudity and fanservice require volume review 参与者：adult male identity in a female body; no central sexual relationship established 年龄与同意：adult identity may enter school-age social presentation; exact chronology and age framing require review 强迫与控制：sisters_experiment_changes_mahiros_body; exact_prior_consent_requires_manga_text_review 暴力与恐怖：no major violence established; involuntary experimentation/bodily alteration is central 待补证：Verify consent details in the manga, Mahiro’s later self-identification, romance, and whether transformation becomes permanent. 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。