I’d say only really small teasers. Iirc, few chapters back there was a flashback with na haesoo crying at the busstop and there was a guy sitting next to her (I forgot if author showed his face or just implied it was him, too lazy to look it up rn lol)
Has the author even showed how he met na haesoo and why he wants her he keeps going crazy over her but we don’t even know the backstory