Master of Lust - Chapter 1: Rick

This is a reincarnation/isekai story, about Matt (later TreeTree), an overpowered tree in a fantasy world that serves as the battlefield for an ongoing conflict between demons and the heroes summoned to oppose them.At first a bystander, over a long period of time, TreeTree will learn all sorts of skills, gain levels, and in doing so, build up a forest, train young subordinates, protect a village, and more.

Sara Fujiharu, the cutest girl in the school, is also known as the 'Seatmate Bully'. Every few weeks, the class seating changes and every time, Fujiharu-san gets a new target. What's her goal? To make the boy sitting next to her fall in love, and once she does, she destroys their heart, crushing their love.

Why does she do this? I still don't know.

It's March 23rd, the day of the seating change. So far, ten boys have fallen for her traps, her playful attitude, her innocent face, not a single boy so far has managed to brush off her attacks-and every single time, their weak hearts have been crushed.

Now it's my turn.

However, my heart is not so easily played with.

What if your own father and his mistress were behind your mother’s death? What if you were about to be sold if to a scumbag?

This world is Heaven.

Because this world has everything you dream of, everything you wish for.

This world is Hell.

Because everyone in this world are parts of a never-ending massacre.

Are you fighting to survive, or fighting to come home?

- Description from Novelupdates