— “Why yaiya with your sweet voice, You tell me you are my best friend” - Best Friend (AKMU)

— You and Yunho had known each other since you were babies, basically your parents are bestest friends and decided to make you both as each other's playdates. And so, many moments spent with each other until both of you are finally adults with stable jobs. Stable enough to get you both a shared luxury apartment somewhere in Seoul.