After waiting a bit to let the anger and rage subside, I'm gonna try to be positive.

Is it an absolute stupid decision ? Yes

BUT Kase is a people-pleaser and as far as I remember she never had to face the fact that she can't please everyone, so it's probably gonna be her learning moment. Hopefully she's gonna realize that and will tell her roommate (who can fuck right off (fucking bitch)) that she is leaving and that's it, then her roommate will be upset with it but no matter, Kase will have learned that you can't be on good terms with everyone.
Technically it's better if characters aren't perfect and learn things in the story (although it still could have been done better)

OR Kase will realise she's not ready for an adult relationship that involves moving in together because she still has that 'high school teenager mentality', she has her 'grown up moments' but they are far and few between. Yamada's going to feel uncomfortable with Kase's recklessness and they'll go on a break to work on themselves. Yamada's come too far in her relationship to be messed around with and if some college room mate's dissatisfaction with her moving out to be with someone else causes Kase to put a hold on her/their plans (something they've been planning since before graduating), over text, then her/their priorities need to be (re)examined. That should be Kase's story arc.

Yeah, what matters is that this should be a learning experience, and it should NOT be resolved with the race.
But to be honest I don't expect a 19-20 yo to be an adult yet

After waiting a bit to let the anger and rage subside, I'm gonna try to be positive.

Is it an absolute stupid decision ? Yes

BUT Kase is a people-pleaser and as far as I remember she never had to face the fact that she can't please everyone, so it's probably gonna be her learning moment. Hopefully she's gonna realize that and will tell her roommate (who can fuck right off (fucking bitch)) that she is leaving and that's it, then her roommate will be upset with it but no matter, Kase will have learned that you can't be on good terms with everyone.
Technically it's better if characters aren't perfect and learn things in the story (although it still could have been done better)

I feel bad about being this disapppointed because I'm aware that it's just another perspective on an aspect of life and I'm just not the target audience. But with that said I think that this work is very badly tagged, it almost shouldn't be tagged as "Yuri" and at the very least be tagged as "Asexual"

HAHAHAHAHA The Church, standing with the people for equality HAHAHAHAHA Best joke I heard all year