The romance story centers around Hana Natori, an earnest, good-natured 25-year-old woman whose cousin refuses to go to high school. Hana takes her cousin's place and attends the high school. On her first day, though, Hana's ruse is discovered by her former high school classmate Okito Kanie — who happens to be the high school's world history teacher. 

(Source: Anime News Network)

It's a new century and men have lost their sexual desires thus decreasing the number of marriages and births. In order to repopulate the world, the government decided to start a program to improve men's sex lives. Sex idols, girls who can sing, dance, and have sex with innumerable men, are now in need to help improve the stagnant society.

Once again, the peaceful morning is shattered by a diatribe delivered by a sister to her brother. This is a daily occurrence at the Utsumi household, and the fact that his relationship with his step-sister, Miyu, isn't improving is a cause of anguish for Mitsuru. While she may behave like an angel in the presence of their parents, when they are alone, she's a pure devil. 
One day, Mitsuru discovers that Miyu has a complex regarding her bust-size. He unwisely brings it up and she blows up at him. While attempting to restrain the raging Miyu, the two lose their balance and fall. Staring into Miyu's face up close, Mitsuru finds himself drawn by her cute features, the warmth of her body, the peculiar scent of a young girl...

The story centers around a timid orphan named Mizumura Shinta who goes to a missionary school in Tokyo. His seemingly normal life changes when a beautiful half-human Romanian girl named Lilith suddenly transfers into his school. Mizumura discovers that he is actually a vampire hunter and the successor of the Romuald lineage.
 
(Source: Anime News Network)

Ryuichi is a university student. He used to live alone and enjoyed his school life. But one day, his apartment was destroyed by a fire.... He reluctantly comes back to his house. But his house has been changed to a boarding house for girls...! It seems there is no place for him to live. But they all allow him to stay there together! His new life begins like this.... 
(Source: Himeya Shop)

Yukiya Ayase is a gentle, kind hearted, and innocent university student. The only relative he has left, his cousin Tetsuo, betrays Ayase by selling him to the highest bidder in an auction with hopes of making an enormous profit to be able to pay off his debts. Somuku Kanou, a bad-tempered (though very rich) loan shark, comes to Ayase's rescue and buys Ayase for an impressive 1.2 billion. Kanou apparently knows Ayase from something that happened between them in the past, but Ayase cannot remember who Kanou is nor does he understand why he "saved" him. In a desperate effort to keep Ayase close to him, Kanou demands the debt be repaid in full and suggests the perfect way to do it: by selling his body to Kanou for 500,000 each time. Ayase is horrified in the beginning, but something soon begins to grow between them that can't be bought for any price.
 
(Source: Anime News Network)

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