Responses
I found it interesting to highlight this issue from the hands of WON had never thought about it. On the glove I always found that Sumin had made a pair and not just one. His perspective of the next chapter and end of this saga I could not agree more.
Rather than Sumin, I believe it's mostly the guilt built over 10 years for the mistake she had done that haunted Seju, because up until now Sumin hasn't really mentioned the cheating again and made it clear that she has forgiven Seju, also because of her low self-esteem and the long-term torture Sumin gave her that pathetically led Seju to the point where she thought she's always the one at fault and could never be forgiven, which answered why she couldn't sleep with any other people than Sumin and tend to push them away one way or another (Nammi, purple head, and now Won). I also believe Seju has let go of Sumin as she admitted in previous chapter it gradually became more like a habit and obsession in order to feel alive. If not, Seju would remember those times she slept with Sumin during her sex with Won instead of Sumin's slap when she betrayed her. So what Seju needs to overcome now is her guilt over the cheating because it happened too long ago and she had paid enough.
My guess for next chapters:
+ Won kept calling Seju "president" even when she has changed their title to "Dowon ssi - Seju unnie" so Seju decided to fire Won as she didn't want Won to bother their boss-employee r/s anymore. I guess it's time for them to be friends, equally. So perhaps the moment Won suddenly comes out of nowhere to save her from the assassin attack will prompt Seju's emotional attraction towards Won, and she will believe that Won truly cares for her as a friend/sister or whatever since she has freed Won from the caretaker's responsibilities, and this will just bring more pain if she finds out Won's still working for her as a bodyguard later on. But maybe Won will tell her the truth next chap who knows lol.
+ Seju realized that just like Sumin, she shouldn't let the past hinder her future if she wanted to move on so she made another single red mitten, completed the pair and goes back to Seoul and returns them to Sumin as the first and also last gift that isn't bought by money Seju can give her, like the time she wondered why Sumin wasted time for a single handmade scarf when she could use the same amount of time to buy 100. And probably, at the end of the story Seju would make clear the things that could cover her cold hands aren't Sumin's leftover mittens, but Won's hands since Gaji kept showing how big they are (also long fingers) from the beginning of One lmao, and now in this chap it was shown that she gripped them tight and not even dare touch Seju here.