Nao's obsession with her brother stops being cute the moment she realizes he might not actually be her brother. The show pivots from standard little-sister trope mockery into something genuinely unsettling about identity and belonging. It's a comedy that suddenly demands you care whether the person trying to seduce someone is even allowed to want them.
Nao is absolutely obsessed with her older brother Shuusuke, and she's not shy about it. The junior high student wages a relentless campaign to make him notice her as something more than just a little sister, which means sabotaging his love life and raiding his room for anything that might distract him from her. During one of these invasions, she stumbles onto a disturbing discovery: a photo album from their childhood that contains no pictures of her at all. Something about their family history isn't adding up, and the revelation sends Nao spiraling into confusion about who she really is and what her relationship with Shuusuke actually means. Comedy collides with genuine mystery as she tries to piece together the truth while continuing to navigate her chaotic feelings. The show balances awkward humor with moments that actually make you wonder what's really going on beneath the surface of this weird family dynamic. It's the kind of premise that starts as pure comedy but gradually reveals there's more going on than anyone initially realizes.