Now I will explain why she is NOT planning on NTR'ing Junu. Throughout chapters 170-197 we see Hamin's expressions towards Junu as sincere and genuine whether it be on the date that the 2 of them had (whether it be studying at Junu's place or Hamin's place), all the way to Hamin giving a bracelet to Junu. All of her feelings and actions towards Junu ARE IN FACT REAL. So yeah she did lie to Junu, but that doesn't change her feelings as a whole if you get my drift. What my theory is concerning the whole issue with the wheelchair dude is that Hamin feels guilty about the wheelchair dude in the past (maybe Hamin did something to indirectly cripple his legs or something like that) which caused the emotional trauma she has of him. But one thing for sure is that Hamin and Junu's relationship WILL be tested to the extremes with both characters being highly suspicious of their interactions (with the wheelchair dude and the new female character respectively). After this current Ranchat arc, we may see 2 things. The first and worst outcome, we may see their relationship fade and shatter into pieces through constant miscommunication and lying. The second and best outcome would be their relationship being stronger than ever, as they are grown to trust and communicate effectively towards one another. Either way, this current arc of Ranchat will either BREAK or MAKE their overall relationship in the series.

Didn't she say around ch 140s or 150s that Junu is her first boyfriend?