The Hero King, Reincarnate to Master the Art of War ~And Thus, I Became The Strongest Knight Disciple (♀) in The World~ - Chapter 13: Inglis, 12 years old

[Mature Smut Contents!]When a deadly virus turns the world into a nightmare, high schooler Ryan gets bitten by an Infected—along with his crush. Facing certain doom, they decide to go out with a bang, losing their virginity in what they think are their final moments.But surprise—they don’t turn. In fact, they’re cured.Turns out, Ryan’s seed has a miraculous side effect: it heals infected women. And that’s not all—he soon discovers unique powers of his own. Now, in a world overrun by monsters, Ryan has a new mission: survive, thrive, and build a sanctuary of powerful (and stunning) women who owe their lives to his very special ability.

In countless worlds, mysterious doors appear, leading to an ordinary-looking convenience store. That is, until you see who’s inside.An immortal cultivator ponders over instant noodles flavor, an ancient demon sips a cola, and a primordial beast carefully holds a bag of potato chips. Beings who could shake the heavens stand quietly in line, waiting their turn.At the counter, a young man scans their purchases. No one knows where he came from, but all understand one thing. In this store, rules must be followed.Welcome to the Dimensional Convenience Store, where even the greatest existences must check the price before they buy.

This is the story of a modern sailor who was accidentally reborn as a soldier of the Brazilian Expeditionary Force, and finally became the largest plutocratic family in Brazil by virtue of his foresight.

- Description from novelbuddy

It’s the vacation of a lifetime, a trip to a remote island filled with geniuses and murder.