Lin Mi traveled through time and became an orphan picked up by Jiraiya. When he became an adult, he replaced Lin and entered Kakashi's class. In order to protect himself, Lin Mi decided to seduce the future boss Uchiha Obito, but he did not expect that Kakashi was attracted by a strange combination of circumstances.
Lin Mi: It's easy for me, don't I just want to live a better life?
Obito: Why are you hooking up with Kakashi again?
Kakashi:... Let's have a threesome