O think is the difference between a really tsunderes and a cornered victim of several abuse.
Everybody thought He was having a tsundere attitude but In reality He was a total psychological mess and everybody just keep pushing him and pressuring him without letting him make up his mind. Now we can see him more relaxed and knowing what he wants for himself, so He start working for that.
He still has some attitude problems, but He is doing this because is happy, not because He is angry and desperate. So that makes it really sweet
Haha I wanna see him graduate from tsundere to yandere lol
i liked the fact you capitalized He when referring to hye-sung. worship that boiii
im gonna be honest. i didn't like hye-sung's tsundere attitude towards dojin around the middle of the story but i found it fucking adorable as fuck (yes i said fuck twice) when they were married and he still is tsundere. i do hope tho he starts being caring and affectionate towards dojin cuz that would just add the cherry on top for me.