Concave and Convex, Soul Exchange

If you don't want to read about the transaction, skip to Chapter 11. Have you heard the story of Soul Exchange? He is famous for his soul trading. Legend has it that the Soul Exchange appears randomly somewhere in the universe, where money is the least valuable commodity and you can trade for everything you have. No one has seen the boss, maybe someone has, but honey, that doesn't matter. What do you want? My dear, you can gain everything you want, as long as you have enough chips... Please remember that the right to interpret all transactions in Soul Exchange belongs to the exchange. OOC warning, soul exchange in the early stage, and bump contest may be written in the later stage. Shijiu has no CP, and the ending is be.