Rebirth: Divine Doctor, Sweet Wife - Chapter 8

Kuramoto Daisuke, a freshman in High School was suddenly exposed to someone vanishing in front of him. Turns out he was admitted to a Special Class full of Isekai Heroes that were regularly summoned to Otherworlds since the start of their Middle School. He was told that he was to become their Support to prevent each of the Heroes' fate of dying in the world they were summoned into. Though mediocre, he realized that his ability has a great potential but it needs a lot of hard work on his part.

Unconvinced of being just the Support Character, he vowed to excavate his mediocre ability, all the while supporting the Heroes using it.

And maybe more.

Other people earn points, gain skills and attributes after transmigration, while I end up planting trees?

Travel to the game world.

Matthew found that there seemed to be a little problem with his system.

…

“Occupation: Necromancer

Task: plant trees

Target: 1000 trees

Reward: Summoned item ‘Bone Dragon’ & a lot of EXP”

…

In this way, a necromancer who respected the way of balance more than the druid was born.

…

- Description from novelbuddy

Kyo Mazuru traveled to the world of Bleach and landed in the forest of Menos Grande at the beginning.Picking up a asauchi left over from Shinigami's death, and starting with a sword, he spent hundred years in the forest of Menos Grande to survive, slashing countless hollows, and his slashing skills reached the peak, until one day, he met a man who claimed to be Mr. Aizen Sōsuke!Mr. Aizen couldn't bear him to live alone in Hueco Mundo, so he invited him out of there and brought him to Soul Society!After that, Kyo Mazuru's Shinigami career began!