In Japan there is this term "Charao" which means a Superficial Flirtatious Playboy. The protagonist, Takeshi Miyamae is senior high student living in Japan is a prime example of this. He always tries to hit on girls and often goes to "Goukons", a term for random dinner dates, where he can meet and talk to new girls each time. He loves women and has had sex with numerous partners to date. He's even gotten a girl pregnant!
One day while going on a class camping trip to the mountains with his classmates, he ends up getting lost in the forest where he ends up in a shrine. There he encounters a fertility godess who grants him an "enhancement" spell to fulfill a task for her.
What's gonna happen with his life from here on?!