Kokan Musou: Kiraware Yuusha wa Mazoku ni Aisareru

Kantaro was reborn into a different world after he died from overstimulated masturbation. Kantaro, who was a fat boy with a twisted personality, was despised by others even in his new world, but he realized that his ejaculate was a universal healing potion. Moreover, it also has the effect of powering up the demons, and so he was desired by them as well.......?! The isekai reincarnation fantasy of a mighty warrior with the invincible crotch!!!

(Source: Yanmaga, translated)