My Level Up Is Strange! ~ Reincarnation of a Great Man in a Different World summary:
Zarmen, a rising adventurer, decided to retire from the adventure business, and to graduate from his virginity, he decided to spend all the money he had saved since his reincarnation in a luxury brothel.
The woman who appeared in front of him was the finest woman he would ever have known. Thanks to her hospitality, Zarmen fully enjoys his first sex, but at that moment, his ears hear a mysterious announcement, "I confirmed my implantation.", "Level up!"
"Does this mean that the more "seeding" you do, the stronger you get?"
An extraordinary implantable foreign world adventure fantasy created by a bottom adventurer who has been at level 1 for many years levels up through sex!