Kokan Musou: Kiraware Yuusha wa Mazoku ni Aisareru

Kantarou ascended to heaven because he masturbated too much and reincarnates in a different world. Being a fatty, he is disliked even after reincarnating, but he 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...!? A different world reincarnation fantasy that is unmatched in the crotch!!!

(Source: Kodansha, translated)