Makoto Raiku

Takamine Kiyomaro, a depressed don't-care-about-the-world guy, was suddenly given a little demon named Gash Bell to take care of. Little does he know that Gash is embroiled into an intense fight to see who is the ruler of the demon world. All of the demons have to pick a master on Earth and duke it out with other demons until one survives. Needless to say, Kiyomaro becomes Gash's master, and through their many battles, Kiyomaro learns the importance of friendship and courage. (myanimelist.net)

With only Coast School in mind, Takamine Kiyomaro leaves Gash bewildered that he'll make a new Volcan 300 for him to play with. The genius tries to catch up with the bus that would take him there, but a giant Volcan 300 kidnaps him. Meanwhile Gash befriends the same Vulcan that kidnapped Kiyomaro later named: Volcan 300 Generation 4. The genius wakes up to see that he isn't in Coast School, but that a doctor by the name M2 wants him to be his partner in the future. (myanimelist.net)