From Manga Freak:
Kusaraki Masao is a normal 15 year-old boy. He goes to school, joined the soccer team, and dreams of a day when he can get a girlfriend. He's nice, gentle, and very, very shy with girls.
And why is this Mr. Nice Guy still single? Well... um... he has a face that resembles a gorilla--hence the nickname--Gorio. Despite his best efforts, Gorio couldn't seem to find a girl who would look past his physical visage to the tender heart he has. Until he met Maki.
Maki is hot, Maki is sexy, and Maki appears to be interested in Gorio!?

The protagonist Hamada Katsuo, is your everyday pervert/loser character. He's starting a new semester in school, so he wants to escape from his loser days, the only problem is the new change in look/lifestyle he got is that of a gang member. He beats a strong guy that was bullying a friend of his by mistake and now, because of it he's the target for all the gangs in the region, even though he's still only a weakling and a pervert. Will Katsuo escape alive...? Find out.

This total loser, Tatsuhito, causes the legendary gang leader of the Grand Cross, Shou, to be hospitalized. He must take his place for the duration of time it takes for Shou to recover or else the Grand Cross would fall into chaos.

Noritaka Sawamura is a teenager; until this day, everybody has been making fun of him. Now he enters the high school which is an opportunity for him to restart a new life! He loves a girl of his school, but he needs to be a little bit stronger to be recognized by everybody. So he joins the Thai boxing section. His entertainment is very special, due to his master who seems to be a little mad. Noritaka will make you laugh, for sure! Note: My favorite passage is when Sawamura spins through a window with a helmet, his trousers missing, with crap coming out of his ass, and everybody looking at him. He is the most ridiculous man in the world at this moment!