Tendo Riku is a detective who forgets anything important after 3 minutes, eats rice in 3 minutes, crap in 3 minutes, and takes a bath in 3 minutes. Although he is full of such flaws, he transforms into the strongest and invincible super detective for 3 minutes when a case is involved! Leads to the resolution of many difficult cases and mysterious cases. His comrades call him "Schwatch", likening him to a hero who fights for only three minutes. One day, Riku is visited by Wako Murasaki, the younger sister of his college friend Kotaro Murasaki. With no relatives other than her brother and no place to live, she relied on Riku through her brother's introduction. Riku is against her girlfriend like that...