Sadamitsu the Destroyer

Synopsis

20 million criminals from outer space—exiled entities—are hurtling toward Earth! Tsubaki Sadamitsu, a pure-hearted delinquent, dons Ponkotsu, a helmet-shaped companion unit designed to recover the exiled entities, and stylishly transforms into Hakaima!! The epic sci-fi battle saga begins here!

(Source: Shueisha, translated)