The flashback.... I'm assuming this was not long before ji-ho and pink lady started messing around? Or is this the night ji-ho spilled beer all over woo-hui and she had to end up changing her shirt in the toilets from chapter 1?
I always thought that Yeonwoo's past lady GF died..... well that's what she told everyone at that bar scene anyway, along with wanting to shave her whole head. So maybe she's not over them yet.... she keeps saying to Jiho make her forget and that she's lonely