The lives of high school freshmen Haruki Mishima and Towa Honda revolve around studying, clubs, and girls. Amid their hectic routines, romance is certainly budding for the two best friends. Since childhood, Haruki has been pining over Miharu Mashiki, and a chance encounter at the convenience store reignites his feelings. As for Towa, the class representative Mami Mihashi has caught his eye; but unfortunately for him, his affections are not reciprocated. While Haruki's more reserved approach to pursuing Miharu contrasts Towa's persistence with Mami, love seems to be elusive for both. As the months fly by, only time will tell if romance is in the cards for the duo.

In the distant past, Miguel, the God of Destruction, was sealed inside the knight who ruled over light and darkness, Sturmhurt. Alongside the knight was Gestöber, who accompanied him through countless battles. In the present day, destiny causes them to reincarnate as Kabuto Hanadori and Seri Koyuki, two classmates. Their reunion should be a joyous moment, if not for the fact that these fantasied heroes are just products of Kabuto's delusions. As the fictional "Gestöber," Seri finds himself in various embarrassing situations due to Kabuto's antics that sometimes grow out of his control. Moreover, his classmate Utsugi Tsukimiya joins the fray with his absurdly accurate mind-reading abilities, slowly destroying Seri's social life. Seri tries hard to stay away from them, refusing to acknowledge their shenanigans, however with Kabuto's chuunibyou and Utsugi's unpredictability, he is only bound to be swept by the craziness coming his way.

Ancient Japan is under attack by powerful beings called "Kamikui," and it is up to the "Oni" and his band of eight beautiful female warriors to stop them. Each of these girls have unique skills, abilities, and personalities. They partner themselves with the Oni, Jin, to stop the miasma of darkness sweeping across Japan. Onigiri follows the escapades of Jin and his merry companions as they strengthen their bonds and fend off the demonic invasion.