Responses
Chapter 25 shows a dialogue between Sunyool and Heejae that shows us Sunyool knows everything and it is clear that Heejae did something bad. Chapter 32 reveals he gets someone to get in contact with Jisuh's ex, you could re-read chapter 31 first to see how Heejae gets interested in Jisuh. Also if you re-read the whole manhwa you'll see that Heejae is the whole time manipulating Jisuh, trying to make him feel guilty, lose his connections to people, etc.
the only problem i have with sunyool is how desprate he is (like quitting school and stuff to work at the same job) *sigh* (im gonna keep it real sunyool just not my cup of tea , like i just dont like him) and that like in this chapter he wasn't really respecting and listening to what jisoo was saying ( i love and appreciate how straight forward jisoo was being) . But i mean sunyool if you have some tea about heejae , SPILL THAT SHIT !!!! i mean its not going to boost your chances but it can hurt heejae chances ( i feel like its something not being revealed about heejae)