Onii-chan ni wa Wakarumai!
お兄ちゃんにはわかるまい！
Keigo Sakaki is a composed and intelligent man who wears glasses, and Maika is a lively, cheeky young woman. They are siblings with a five-year age gap, though they share no blood relation. Keigo works as a prominent announcer and frequently attends to Maika's requests. The story explores their unusual relationship in a comedic and romantic context.