Doha, the protagonist and male lead, is an insufferable character throughout most of the story.
He treated Jihye poorly despite all the effort she gave to be supportive of him and wanted to be his girlfriend. When Sohee confides into him about Dohoon possibly cheating on her, Doha gaslights Sohee that Dohoon isn't that type of guy despite hearing Dohoon wit a other woman over a phone call prior. He tries to confess his feelings to Sohee even though she's an unavailable woman.
Sohee, the female lead and Doha's long time crush, is a wishy-washy, weak woman that in some parts, deserves an asshole like Dohoon because she's too cowardly to be true to her own feelings.
She has several sexual encounters with Doha and then pleads with Doha to forget that they happened or she pretends not to remember because she was drunk. Doha even catches a shady man taking a drunk Doha too a motel and the man has sex wit her, but once Doha arrives she and the man denies anything happening between them. After catching Dohoon cheating with Jihye, she kicks him out of their home and has sex with Doha. She breaks up with Dohoon and then also breaks contact with Doha by changing her number and moving away.
Dohoon, Doha's older brother, is a certified womanizer and cheater.
He constantly cheated on Sohee and it makes you question how Sohee even started dating him. He even tried to get sex out of Jihye while he is already dating Sohee and noticed how affectionate she was being to Doha. At the end of the story, he finds another woman to marry.
Jihye is pretty sympathetic. She deserved better because she initially was a girl called over to give Doha a good time to forge his break-up with his girlfriend who cheated on him.
She starts developing feelings for Doha and has tried to become his girlfriend. Doha abandons her often and later rejects her for good. She tried to help Doha one last time by having an affair with Dohoon while also arranging Sohee to walk in on them and break those two up.
The story had an okay start but quickly got messy once it was revealed that Sohee and Dohoon were dating. I would've preferred if things went in a different direction.
Jihye's gambit became pointless because Doha and Sohee still didn't end up together. After Sohee moved and changed her number, Doha spent over a year looking for her just for the two to meet by happe stance and the story ends. The author made it an "Open Ending" thus, making everything pointless.