Soulmates 《Xiumin》

[Info: English is not my native language so please don't mind if I do any grammar mistakes.]

Having a second soul might sound really cool. Like an invisible friend you can talk to all day, that secretly helps you to cheat on tests and just makes your life a lot more fun. But their purpose and the reason of their appearance have a way deeper meaning.
Also they are quite unique and some people would do anything to have such a second soul...