Oniichan dakedo Ai sae Areba Kankeinai yo ne!

Oniichan dakedo Ai sae Areba Kankeinai yo ne! centers on Akito and Akiko Himenokouji, brother and sister who spent six years living apart in different homes after their parents' deaths. When they are finally reunited, they move in together again, and what should have been a quiet family reunion quickly turns into an emotional minefield. Akiko is openly in love with her brother, while Akito can only think of her as his sibling, so their new life under one roof becomes a tense mix of jealousy, denial, and shifting boundaries as both try to adjust to a relationship that means very different things to each of them. The chaos escalates when Anastasia Nasuhara, Arashi Nikaidou, and Ginbei Haruomi Sawatari also end up living in the same apartment. With the hope of having Akito to herself slipping away, Akiko finds herself competing with the three newcomers, each of whom is drawn to Akito in her own way. Their shared home becomes a constantly escalating domestic battleground full of misunderstandings, flirtation, and erotic mishaps, as the girls scheme, argue, and sabotage one another for a chance to care for Akito and win his attention, while Akito struggles to keep up with the storm building around him.