
I'm confused,Chiwoo made a wish that Hwan would like him but then why is he telling him that he likes him again and that he won't remember it later.Doesn't Hwan already like him because of the wish?

Chiwoo didn't wish for Hwan to like him though. Chiwoo wished to go out with him. And now that he told Hwan he likes him, Chiwoo has every reason to believe Hwan will forget that once he defeats the monster, because everything that happened during the attack is reset after the monster is gone, including people's memories of the events.

I'm confused,If this manga isn't supernatural...what could be inside the black room

This manga is most likely something with trauma, mental disorders, or ptsd. He obviously is recovering from some trauma that happened within that house. The brain sometimes covers trauma unless something trigger it. Or not cover the trauma and still be triggered. It also seems like he has some issues with loving someone. I could be wrong!
Why is nobody talking about Taesung's dad's secretary