so this website is missing chapter 13 and basically what happens is this :
Spoiler!
mari slowly recovers and after she's fully recovered, she talks dawol aside and talks to him abt their relationship; she thought she was fine with their relationship being one-sided (her liking dawol but him not returning his feelings towards her) but she doesn't want to make him sacrafice himself to be w/ her bc it's only making them both suffer. they break it off so dawol goes to meet up with ji-hyuk and tells ji-hyuk "oh ur confusing ur feelings for someone else w/ me" and then sets him up with kiyeon
you can read ch 13 here: https://comiko.net/chapter/2019347 (mari is fine obv bc she's dating me now)