Kindaichu Shounen No 1-paku 2-ka 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.
As goes without saying, this manga is a comedy spin-off of the popular work Kindaichi Case Files!