Kiyotaka Ayanokouji enrolls at the prestigious Tokyo Koudo Ikusei Academy, but is assigned to Class 1-D, where students with behavioral problems are housed. The school awards points equivalent to 100,000 yen per month and allows unusual freedom in classes, masking a more complex system.

Issei Hyodo is your average perverted high school student whose one wish in life is to have his own harem, but he's got to be one of the unluckiest guys around. He goes on his first date with a girl only to get brutally attacked and killed when it turns out the girl is really a vicious fallen angel. To top it all off, he's later reincarnated as a devil by his gorgeous senpai who tells him that she is also a devil and now his master! One thing's for sure, his peaceful days are over. In a battle between devils and angels, who will win?

Thirty years ago a strange phenomenon called a "spacequake" devastated the center of Eurasia, claiming the lives of at least 150 million people. Since then, smaller spacequakes plague the world on an irregular basis. Shido Itsuka, a seemingly ordinary high schooler comes across a mysterious girl at the ground zero of a spacequake and learns she is one of the "Spirits" who are the real cause of the spacequakes that occur when they manifest themselves in the world. He is recruited to make use of his mysterious ability to seal the Spirits' powers thus stopping them from being a threat to mankind. However, there is a catch: to seal a Spirit's power, he must make her fall in love with him and kiss him.

A new school term begins, as does the season of new encounters. As he surveys his class full of couples, Hashiba Jun'ichi's mind is filled with distress as he asks himself, "Why am I still a virgin?!" Having heard from his friends that the easiest way to fulfill his long-standing desire to graduate from the fellowship of virgins is to kowtow to a gal, Jun'ichi does exactly that and asks his classmate Yukana out. And unbelievably, she actually agrees to date him. What will become of Jun'ichi from now on?

Naoya Mukai has loved Saki Saki since grade school, and when she finally accepts his feelings, he's at his happiest. But one day, a cute girl named Nagisa Minase confesses to him! Not wishing to choose only one over another, Naoya chooses to go out with both of them!! What will be of this love triangle that challenges morality itself?

Dog Days takes place in the world of Flonyard, an alternate world where its inhabitants look like humans but with animal ears. When Cinque Izumi suddenly gets summoned to this alternate world he is appointed as a Hero. How will he lead his life and interact with the various characters in this new world?

Deemo is a lonely individual who lives in solitude, playing the piano in a castle. One day, a girl who has lost her memory falls from the sky. Wanting to help her recover her memories and return to her world, Deemo discovers that a tree kept atop the piano will grow whenever the piano is played.