Konjiki no Gash!!

Kiyomaro Takamine, genius middle schooler, is greeted one morning by Gash Bell, a boy with a mysterious red book. Tasked by his father to decipher it, Kiyomaro soon learns Gash is no ordinary boy. Able to shoot lightning from his mouth at the chant of a word, Gash is a demon child—one a part of a war that takes place every 1000 years to decide the Demon King. With Kiyomaro being the only one who c...