Grave King!

Soichiro, who died from choking on his own vomit in his sleep, is asked by a God (tentative) to be reincarnated on Earth with magical elements. After agreeing to this, Soichiro is reincarnated in Asgard and begins learning magic there. While he has abundant magical power, he can barely use local magic. But what if he mixed in modern knowledge?! Struggling with unfamiliar magic, he uses magic for comfortable living before combat spells—such is his daily life. Then one day, after discovering that Soichiro's bodily fluids (various kinds) are useful for magical recovery, his life changes completely, mainly in terms of where he sleeps. ※This is a typical harem-adjacent slightly erotic story.