The Kazama Family—a gang of three wannabe delinquents and close friends, spearheaded by Kenji Kazama, is trying to make a name for themselves at Fujou Academy. On the first day of the term, the gang finds themselves putting out a fire in the Game Development Club. Instead of thanking them, the eccentric club members attack and knock out Kenji's two friends, forcing Kenji to fight for his life. Failing to escape, the gang leader is coerced into joining the Game Development Club. As he settles in, Kenji gets to know the four girls responsible for his provisional membership—student council president and general tyrant Chitose Karasuyama, spirited tomboy Sakura Mizukami, negligent club advisor Minami Oosawa, and the school's infamous shadow leader Roka Shibasaki. Throughout the Game Development Club's constant shenanigans and his desperate attempts to leave the club, Kenji begins to realize that he may be actually enjoying himself. [Written by MAL Rewrite]

Naota Nandaba is an ordinary sixth grader living in a city where nothing amazing ever seems to happen. After his brother Tasuku leaves town to play baseball in America, Naota takes it upon himself to look after everything Tasuku left behind—from his top bunk bed to his ex-girlfriend Mamimi Samejima, who hasn't stopped clinging to Naota since Tasuku left. Little does Naota know, however, that his mundane existence is on the verge of being changed forever: enter Haruko Haruhara, a Vespa-riding, bass guitar-wielding, pink-haired psychopath whose first encounter with Naota leaves him with tire tracks on his back and a giant horn on his head. Though all he wants is some peace and quiet, when Haruko takes up residence at his parents' home, Naota finds himself dragged into the heart of the greatest battle for supremacy that Earth—and quite possibly the entire universe—has ever seen. [Written by MAL Rewrite]

One year before the beginning of the story. Kaguyama feels intimidated by Haruna’s presence on the baseball team since he feels that his position as the ace pitcher is threatened. Kaguyama wants to quit, but Haruna talks him out of it after telling Kaguyama about his own past. (Source: Wikipedia)

Two OVAs released with the 8th and 10th volumes of the original novel. They fall chronologically between the first and second seasons.