Back when the chapter came out a lot of us noticed the red mitten and assumed she was going back to Sumin but then that whole theory was debunked by what happened next. The plane thing was always meant to be work related (not because of Sumin) if you pay attention she had received a work email before and she couldn’t stay with Won after she was hit because she really needed to go back for the company meeting, so prior Won getting attacked Seju had already settled to give up her shares of the company, that’s why she went back to Seoul. The red mittens are more like symbolism of Seju reminiscing her memories with Sumin and trying to let go of the last leftover love she was keeping, the following chapters confirm it as she tries real hard to move forward.
Her suddenly deciding to NOT pursue Sumin again (if we’re going to believe that’s what she was planning to do) just because Won took a hit doesn’t make sense but also her deciding to GO back to Sumin overall just doesn’t make sense either, having in mind she was the one who left Sumin so she could be happy, so yh.
Nice interpretation (๑•ㅂ•)و✧
In Chapter 117 when Seju had glimpse of Sumin’s heartbreak, she realized that she’s still in love with her. Then the next day she booked flight to go back, I assumed she wanted to pursue Sumin again (did you notice the red mitten that Sumin made for her on the table? chapter 118). Gladly that never happened as her brother came in - try to kill her - Won saved her etc.
Well, I just want to point out the red mitten, lol. (๑•ㅂ•)و✧