22-year-old Rin has two major problems: a complex about the tattoo-like birthmark on his butt and a crush on an older woman who thinks of him as her little brother. Rin hasn't allowed any woman to see his naked bottom since an incident when he was 7, which firmly entrenched his shame about his birthmark. When he finds his birthmark may grant him mystical powers over the opposite sex, will he finally be able to use his butt to his advantage?

Himekawa is 26 years old and has a beautiful girlfriend who wants to remain a virgin until she's married. He's lied to her and told her that he has a career with a company when in fact he works at the local convenience store. Ashamed, and wishing to power up his career so he has a shot at actually marrying his girlfriend (and her virginity), Himekawa replies to a want ad and is surprised to get an immediate response.

The response comes from a dating services company that wishes to test their computer dating algorithm, and he's a perfect match for the no-nonsense Ino-san. He can get a job with the company if he can validate their algorithm by getting Ino-san to agree to marry him within a month!

"Progressive Rejuvenation Syndrome." This is an extremely rare disease causing the inflicted person to gradually become younger. The main character of this story, Munenori Agawa, is the only person that could save Rena Amami from this odd disease. Agawa's saliva is the only thing that can halt the disease from making Rena younger, so they must kiss everyday in order for her to survive. This causes an immense amount of conflict and drama between Agawa and his new girlfriend, Sayako Asou. This triangle relationship story tests the capabilities and limitations of human love.

A man who's still a virgin, has a very very rare disease that only allows him to have sex 7 times in his life. After he's used up all 7 of the chances, he'll never be able to have an erection and ejaculate, which means he will lose his ability to have sex for the rest of his life. So far, he has wasted 2 times while masturbating, so he's left with only 5 more chance to have sex. He has to save those precious bullets, but at the same time he desperately want to lose his virginity.Included one-shot:
Volume 4: Senpai no Kanojo to Heya de

Ever since he was a child, Tachibana Hideo has wanted to become a superhero like in the TV shows he watched. After he graduated from high school, he got into the Kantou Films School to chase this dream. In the summer beforehand, he managed to get a part-time job as a costumed villain for a "Crashman" heroes live show. Unfortunately, he got a little too into it, kicked the heroic "Crash Pink" in the face, and got himself fired. As he later discovered, Crash Pink was his future classmate and aspiring actress, Mutou Sakurako! Livid that he'd dare damage her precious face, she insisted that he make up for the injury, mostly by putting up with her constant efforts to torment him. But as they spend time together, could something much sweeter than mutual annoyance be growing between them?
(Source: MU)