As a punishment game, Mikoto had to buy a dildo. But of course what is he gonna do with it when he doesn't have a girlfriend or anyone to use it on. As an extra gift, some jelly beans were given to him when he bought it.

He decided to see how it worked before he was going to return it. However, when he ate one of the jelly beans and turned it on, a light shinned and the dildo turned into a man! It turns out this man is an alien prince! And has fallen in love with Mikoto, he even wants to marry him! A love comedy ensues!

(Source: MU)