Welcome to the future. In tried-and-true sci-fi fashion, the date is given in a time system that we have no reference for, so I can't tell you how far into the future we are beyond saying that it is S.E. 156. Thirty years before our story begins, an ace space pilot by the name of M2 Rimstein was put into an experimental cold sleep until such time as he would be needed.
That time is now. He is unfrozen and put in command of the Dance Mania unit of three superb pilots, though two are rookies: Stellasta von Argyll, Malloy Chihaya, and Cloud Neelsen. Accelerated training commences, and new ships and gadgets are brought out so that they will have victory over their enemy.
Unfortunately, things go awry fairly soon when M2 is captured and brain-washed by a planet which sends him out to fight for the enemy. Malloy at first refuses to fight his commander, and then does so with the conviction that he can bring him home to the Great Carrier.
Bringing him home may be easy, but regaining his mind?
(Source: Translated Treasures)

Yukimi, a chubby junior high student, discovers a magical dumbbell that can transform her into Miyuki, a beautiful and slender young woman in a revealing costume. But she must do battle with an evil three-star chef who tempts young girls with calorie-rich treats and dubious weight loss products, and keep her identity secret from her family and schoolmates. (Source: M-U)

Tsubaki Ooshima and Tsumugi Ooshima are very cool twins and gay. When they were students, they tried to have a sexual affair with Tougo Hayakawa, their classmate, but was found out. Exiled from their home by their father, now they are enjoying urban life on the camper with hunting boys...

The story of Kuraku Asuka, a tough junior high student who gets involved with the gang scene in the Kabuki Chou Ichibangai, a rough area of Tokyo. (from Lililicious)

From Possible Soup:
Hokuto is a first year student at a famous athletic school... however, he doesn't happen to play any sports due an anxiety problem that he had developed. Now, after being pressured by his friend Yuri, he has become the manager of the basketball club. Strange things start to develop as he gets harassed by some of his senpais and begins to battle some demons...

University student Sekiguchi Toshihiko's life takes a turn for the bizarre when he begins working as an accounts clerk with Galaxy Planning, a small firm that serves as a front for organized crime. His boss is the ultra-cool Aguri, a devil-may-care yakuza with a passion for gratuitous violence and endlessly harassing his favorite employee.

Harumoto Akira, a talented high school music student, descends into the violent world of Japanese speed tribes thanks to his obsession with Otoguro Yugou, the manipulative and enigmatic leader of the tribe, Red Kreuz.
(taken from Baka-updates)

High school student Nanamura Hikaru has little memory of his deceased father, a famous playboy actor, until his father's suave attorney, Shimogura, contacts him with the promise of a sizable inheritance. The catch? Hikaru has to make contact with each of his eight half-brothers - the fruit of his father's philandering ways.

From Blu:

Watch as the worlds of anime voice acting and high school hockey collide! The boyishly handsome Shino is greeted at his front door one morning by the seventeen-year old son he didn’t know he had. Suddenly pushed into the position of being a father and a provider, Shino starts taking on new acting jobs, including boys’ love drama CDs, and the separation between art and life narrows significantly when his new coworkers start taking quite a bit of interest in him! As if that weren’t enough, his son Nakaya is a handful in and of himself. An aspiring hockey player with a bit of an attitude problem, Nakaya has a lot of growing up to do, and Shino is in for the long haul.

Shuuiku Academy is an elite all-boys school, home to a dormitory full of aspiring young students. But when the dorm’s lights go out, the exited cheers of handsome young men fill the hallways! Watch as love and ambition bloom in this wildly popular boy’s dormitory tale