Sundome Jigoku no Cherry Boy

Virgin Yuji Ubakata dies without ever experiencing sex, and when he lands in hell, he is greeted by the swimsuit-wearing god of hell, Enma! She tells him that he must face retribution for his life as a virgin, and he is sentenced to a very unique punishment... Yuji is then taken to another room, where he finds Mayu, his first love! "Now, as punishment, you must touch each other's bodies!" What? That's the punishment? It's not hell, it's heaven!

(Source: Coolmic)

Note: Published in 18 episodes, compiled into 6 long-form chapters.