Ritsuka Tachibana has always been a good student, so she is completely shocked when she is suddenly summoned by the student council. Even more, they seem to think of Ritsuka as a troublemaker. Led by the handsome Rem Kaginuki, the student council—also consisting of Urie Sogami, Shiki Natsumizaka and Mage Nanashiro—tries to question her, but it soon becomes clear that they have ulterior motives. However, this is only the beginning. When her mother gets kidnapped, her life is turned upside down, and Ritsuka gets drawn into a world of vampires and devils. Both groups are searching for the "Grimoire," a forbidden item allowing its owner to rule the world. The return of her brother Lindo from overseas gives her hope, but even he appears to be hiding something. In a world filled with secrets, Ritsuka questions whom she can trust in this dark musical tale, while the handsome and dangerous members of the student council compete for her attention. [Written by MAL Rewrite]

Haruki Nakano lives an average high school life, except for the fact that his mother is overseas and he shares an apartment with his four sisters. There's the oldest, Mutsuki, who has a bad habit of falling asleep in his bed, the junior high school student Yayoi, who hits him whenever something happens, and then the grade school twins, Uzuki and Satsuki, who love to play pranks on their older brother. Stuck in a house with four girls, Haruki has to deal with all sorts of trials. From going grocery shopping, watching scary movies, to kissing practice, life is never boring in Danchigai!

High school student Takeru Takemoto works part time as a (motor)bike courier. During one of his deliveries, he saw a mysterious light passing him and fell into a forest. What he had found was a beautiful girl coming out from a glowing cocoon, calling herself "Hikari." While Takeru was quite embarrassed because of Hikari's nudity, a strange monster suddenly showed up and immediately attacked the two. Both Takeru and Hikari demonstrated the power of their other selves before Takeru had a clue of what's going on. (Source: ANN)

At the end of the 21st century, Earth had to confront the problem of population increases combined with shortages in resources. Development of the Moon was seen as the way to solve the situation. The Moon's mineral resources reinvigorated the Earth and brought prosperity. However, the achievement of that vision proved painful for those who'd left their home world to settle on the Moon. One of Man's greatest dreams has become a nightmare for those who have been forced to live it out. Shun Nonomura doesn't realize it, but he's about to discover a weapon—one that can overthrow the oppressive Monopolice and bring freedom to the lunar colonists. The growing resistance movement is quick to adopt it, along with its creator, into their ranks as they rally around the mysterious alien monument known as Dallos... (Source: AniDB)