Taku.

I don't really like Taku that much, but he honestly deserves better. A very dangerous characteristic of Taku (+and Haesoo) is that he is empty and engaged to fill this through selfish love, something that really won't solve anything. It's concerning that someone is willing to be used and experience fake feelings instead of moving on with his life.

He had never loved someone, Taku saw his previous partners as candies that lost their flavor the more he ate them. He joined the sweetness not because he really wanted to but because it was what they expected of him. But Haesoo was different. His apathy attracted him even though he wasn't on board with the idea of experiencing it. Taku, in addition to seeing the possible taboo relationship he had with Joowon, liked the concept of Haesoo. Someone who is broken, someone who needed him. Taku admits that it was not difficult for him to get close to Haesoo because he already knew the root of the other's pain in a certain way thanks to his stories.

But this was also his biggest mistake, taking them so seriously that when Haesoo leaves the character that Taku knows, he doesn't understand. Taku doesn't really know Haesoo, much less the relationship he shared with Joowon. Taku never knew Haesoo or Joowon beyond Haesoo's narrations. That is why every time one of the two proves to him that he has no idea how strong and complex their relationship is, he gets stressed. Their history no longer attracts him.

He will not be a victim because he always knew what he was getting into, but Taku has an emotional void that he will not be able to fill with someone who sought comfort from him in the wake of someone else. He is getting so much hope for something that is so empty and shallow, it's kinda hard to read.