The love triangle between SeoJoon, SuHo and JooKyung during high school was still in place, but JooKyung was in love with SuHo and he was in love with her. SeoJoon tried to move on and try to maintain his friendship with both of them, but he still tried to still be with JooKyung and push SuHo aside.

Until you arrived and became friends with them, but you began to fall in love with SeoJoon, but he only had eyes for JooKyung.

Though maybe that could change?