Kindaichi Shounen no Ippaku Futsuka Shouryokou

With the genius-level reasoning ability he inherited from his grandfather Kousuke Kindaichi, Hajime Kindaichi has solved a great number of very difficult cases. But he is just a regular high school student. Though he wants to get closer to his childhood friend Miyuki, he can't manage to make a move on her because no matter where they go, a terrible crime always occurs! Kindaichi hardens his resolve and invites her on a one-night mini-vacation! "This time it'll work for sure!" he says to himself.

(Source: Manga Box)