Imasugu Onii-chan ni Imouto da tte Iitai!

Following his father’s remarriage, Rikuto gains a younger brother named Ayumu, unaware that she is actually a girl pretending to be male at her mother’s insistence. As they spend time together, Rikuto finds his heart racing around his endearing sibling, while Ayumu suffers in silence, burdened by the secret she must keep from her compassionate brother. Their complex dynamic shifts with the arrival of spring when they enroll at the prestigious Asaoka Academy, where Ayumu finally attends school presenting as her true female self. At their new school, Rikuto begins forming friendships but soon realizes his classmates are each grappling with personal struggles regarding identity and self-expression. His middle school friend Matsuri has lost touch with her femininity, the stoic Mao disguises herself as a boy despite being female, and the painfully shy class representative Kimika desperately wishes to transform herself. With Ayumu faithfully by his side, Rikuto dedicates himself to helping these peers rediscover what they feel is missing, navigating the delicate intersection of gender, friendship, and self-acceptance in this heartfelt story of hidden truths and emotional growth.