Jibro

Nikaido Katsuo, AKA "Fist King", is the most powerful and undefeated delinquent in Japan. However, no one knows that behind the stories of his legendary battles, there is a girl behind the scenes... Her name is Tabara Nikaido. She is the fighter who took her brother's name and fought in secret, and defeated all the strong men in her way...Alt Official Raw: MagaPoke

Kantarou, who has ascended to heaven because he is too sick, reincarnates in a different world. Kantarou, who is distorted in character and is a fatty, is disliked even after reincarnating, but notices that a cloudy potion that cures anything from his crotch appears. Moreover, it also has the effect of powering up the demons, and it will be loved by the demons...!?Alt Official Raws:Comic DAYSniconico Manga