I, my cousins and many classmates had died in a bus accident on the return from Summer Camp.
Before reincarnating I was offered a proposal, if I accepted, my cousins and my colleagues would reincarnate in a good life, the better the relationship we have, the better the living conditions, in return I would be reborn randomly, being any kind of creature, from a man to a tree, from a humanoid monster to an animal monster.
For my cousins to have a good life, I accepted the proposal.