Tsuda Takatoshi is about to begin his first year in Ousai Academy. His decision to enter Ousai was based upon it being close to his home and he paid no heed to the fact he'd be among the first boys to enter the recently gender-integrated school. 
On his first trip to school, Takatoshi is surrounded by girls; the train has nothing but girls, the walk to school has nothing but girls and once he finally arrives he is approached by a group of girls and summarily appointed vice-president of the student council and, as expected, he is the only boy there. 
Now Takatoshi finds himself surrounded by crazy girls who do nothing but horrify him with their candid conversations about feminine hygiene products and, what's worse, assume he's the worst kind of man, the kind who doesn't clean himself and watches porn all day long.

Arima Teppei lost his parents in a traffic accident. His grandfather Isshin adopted him by force and ordered him to succeed the head of Arima Group Corporation. At Shuuhou Gakuen, a high school only for wealthy students, Teppei's new life as a celebrity starts.

Based on the erotic game by Alice Soft. 
 
Two large countries, Leben and Carnea, had been ruled by the kings who were men of character, and people in these countries had been living peacefully. However, Leben suddenly intruded into Carnea, and the two countries began to war. 
 
The even fights had continued for more than six months, but when the king of Carnea died of illness, gradually Leben got the better of Carnea. 
 
In these days, a man in a black suit visited Carnea. He had been a vice leader of the Carnea Knights, Claude, who had suddenly disappeared eight years before. His appearance had changed completely, and that made them suspicious. But when he said he had a plan to beat Leben, they gave their ears to him. He said that they would hire experienced mercenary solders, and that the queen and princesses would sell their bodies to earn money. The queen and her daughter accepted his plan, and they began to take his "lessons". 
 
(Source: AnimeNFO)

A series of OVA episodes released with the limited edition manga volumes. Episode 01: What You Gave Me (Anata ga Watashi ni Kureta Mono) 
Kokonoe, Usa, and Kagami go shopping for a present for Sensei. Eventually Kokonoe decides to make one and they all end up spending the night at her house. Along the way we learn more about Usa's love for Reiji, Kagami's love for Kokonoe, and Kokonoe's love for Sensei. Episode 02: Kuro-chan, Shiro-chan (Kuro-chan to Shiro-chan) 
Kuro-chan tries to become friends with Shirai-sensei. Episode 03: A Child's Summer Time (Kodomo no Natsu Jikan) 
The girls, Aoki and Houin go into the country to visit Aoki's family.

3rd grade teacher Aoki Daisuke didn't expect the first class he ever taught to be one of the toughest obstacles of his life. After getting off on the wrong foot with the entire class, a moment of kind-heartedness instantly convinces one of his students, Rin Kokonoe, to make the ill-fated Aoki-sensei her lover. But what exactly are Rin's intentions for wanting to actively seduce Aoki-sensei, and will Aoki-sensei be able to help her to deal with them?

Mizuho can't believe his ears when Grandpa's will is read out. Grandpa's final wish is for Mizuho to attend the same academy as Mizuho's mother. The catch is it's an all-girls school. With the help of friend Mariya however, he gets a makeover good enough to fool everyone at the academy. 
(Source: Anime News Network)

With a two-tone hairstyle and a streak of immaturity, Hikaru Shindou finds an old Go board with a hidden surprise - trapped within the Go Board is Fujiwara-no-Sai, the ghost of an ancient Go master! In the blink of an eye, Sai becomes part of Hikaru's consciousness and soon begins to learn the true essence behind this ancient game of skill and strategy. 
 
(Source: Viz Media)

Dream Force