Tantei no Susume ~Kurenai no Reppu Hen

My name is Miki Fujiwara. I'm a totally normal cute high schooler.
Things were pretty normal for us until one day at the library, an arrow came shooting!
It carried the warning of a future crime by someone known as "Red Cap":
the night after next, a bomb will destroy the east campus!?

High school detective Miki and her sidekick Sato-kun are on the case!

[From DLsite English]