He's even doing things he hasn't done before, the first most noticeable one was when they went out to buy clothes for mittens in the DAY. Jooin going with him to do groceries which he doesn't even do, his attempts of cooking for him which he hasn't done, and honestly I'm counting how he hasn't slept with anyone for the entirety of Mittens being w him. Two broken people living together while healing each other's broken parts, definition of soulmates
+ him slowly not eating cereals or ramyun anymore but more on Mittens cooking and his own, also him not rising up at night time but sleeping during it
I love how you can actually see Jooin's attempts on being a better man even if he himself isn't aware of it, like when Mittens fell sick and he cleaned up their mess? This flavour of characters makes me sob man. They aren't just healing for their partners, but also for themselves