That would be irrelevant and unnecessary. Taku is simply a side chara whose part in the story is to bring conflict. He did his part and even given a happy ending (tho I have issues with that). He's served his purpose so he's done with for good. Next.
I wouldn’t really call him a side character. He was in more or less every chapter. His character was given a lot of depth and he had a back story I would’ve called him just as much of a lead as the guy haesoo ends up with. Idk why you’re You have an issue with him having a happy ending when he deserved one. He’s been in it all the way through why would they just completely write him out at the end??
I liked the ending I just wish they showed more of taku and how he got on with his life in the future