サイレン鳴ったら、2秒でえっち!?

The main character is Minagi Sakai. He just started working for a clothing design company. But that same morning he also hears a strange siren on his way to work. As he listens to it, it gradually arouses his libido. He tries to forget it, but people around him start having sex. Siren and sex.... What's going on in this town...?

[From ErogeShop and English DLsite]