(You're Childe, and you're his FWB.)

You two met at a relative wedding. He wasn't your relative, just a friend of the the relative that was getting married, not to mention his calmness and your mischievousness which put you two to be completely different, yet you two still managed to get along. Now, you and him had gone to college, smoking weed in the abandoned gym nearby to release stress, and had your fair share of affairs whenever needed.

Also, Kazuha now had secret feelings to you now.