Natsume-kun wa Nandemo ShitteruNatsume-kun Knows Everything; Natsume-kun wa Nan Demo Shitteru; なつめくんはなんでもしってる

Yousuke and Natsume are childhood friends. Yousuke assumes it's natural that Natsume would know a lot about him, seeing as they've lived next door to each other for years, but one day, he discovers a secret...