Bin is the daughter of chowon and Kyungsoo. So yi is the daughter dojun and heesoo. Byul is the son of Dojin and hyesung. Dojun and chowon were ex husbands. Heesoo is the best friend and same band of Dojin. Kyungsoo is the best friend of hyesung. Dojin and dojun are brothers. Siwoo is byul’s boyfriend. So yi has the crush on byul. If you want to read the parent’s story it’s “love is an illusion”. I hoped that helped!

I can't keep up with the comments who's who!??