I was a student who had failed entrance exams and lived in an old rental house. There was a married woman living next door, but she was cold towards me because I was not very attractive. Then, one day, a "G" appeared in my room, and while I was trying to get rid of it, I hit my head and lost consciousness. Then, when I woke up, I had become a "G"! What should I do... but wait a second? A "G" can spy on the wife next door!? I immediately went to peek, and found out that the wife was cheating on me. Now that I knew that, it was time for "Mr. G" to strike back...! But how could I turn back into a human?!