Season 1

Aika, the new younger sister of Kota Takamura from his father's remarriage, is a super sassy gal who bluntly calls her stepbrother “lame” upon first meet. Calling each other names, with each holding the worst impression…

That day, Aika was indulging in intimacy with her boyfriend Takahashi in her room as usual. However, a certain situation stirs trouble between them. To make matters worse for Aika, Kota, who had heard the commotion, sho…

Despite Aika skipping school and bringing boys home—behavior that could be called delinquent—she hides it from her parents and acts like a model daughter... Living together, Kota witnesses her dual nature firsthand. One…

That night after the incident in the bathroom, Aika and Kota each lay in their own rooms, lost in thoughts of the other. Aika replays Kota's words and actions in her mind, sensing something different from the guys she'd…

Aika still lets Takahashi into her room, although today she seems unusually reluctant. The tactless Takahashi doesn't seem to care however, teasing that all guys get horny around the sexy Aika. Aika snaps and slaps him …

Kota narrowly defeats Takahashi and succeeds in protecting Aika. But now, with Aika still in her disheveled state, she asks him to hold her tight, leaving him flustered. Out of a sense of responsibility as her older bro…

The emotional and sexual tension reaches its peak: Aika and Kouta share tender and explicit moments, almost crossing the line completely, but with interruptions and hesitations. Their bond strengthens amidst the forbidd…

The Takamura family heads to Atami for a family trip. Encouraging their parents to enjoy some time alone as a couple, Kota spends the day sightseeing by himself and fully enjoys the vacation. Later, as he returns to th…

The Takamura family continues in Atami! Aika and Kota arrive at the beach. While Aika is strolling alone in her swimsuit, she is approached by a man. Although she is annoyed, she tries to avoid the situation peacefull…

Now it's become perfectly normal for Aika to read manga in Kouta's room. She brings all the volumes out to read them all at once in the living room, but the moment she sees the dark hallway, she becomes strange and deje…

Aika realizes she feels both excited and satisfied from her physical closeness with Kouta. Then at that moment, the image of a certain guy who once boasted that he'll teach her what real love is, flashes through her min…

Aika boldly barges in on Kouta's bath time, holding a trendy bath bomb. Meanwhile, Kouta, concerned by Aika's tears he saw in the ruins, blurts out something that spoils the mood. However, Aika's reaction was different …