Not for the light of heart. Also, not yuri, though it was published in a yuri mag
There's the temptation to blame Koma, I know, but caregiver burnout is a real thing and they're kids...damn
This feels real, while being incorporated with otherwise unreal imagery, things you don't even notice early on until you go back and read it.
I want to comment and discuss more but really it'd be major spoilers.
It's great. But you won't feel great.
Notice how when you go back to the first pages, they weren't at the beach. I was confused cos we saw the rising tide, I thought this took place in the future where sea levels were high enough to reach a park :p
Nope. This is Koma and Yura at a normal park, the rising tide is in Koma's head.
Yura desires death...but Koma is already feeling the pressure, as if she'll drown one day.
While reading this series you feel as though Koma doesn't care about Yura, that she wants things to stay the same in her chill life. When in actuality what she desires is, if not an easing of the rising pressure, then at least that things don't get worse! Cos she's suffocating, she's burning out, she cares for Yura but if a time comes that Yura leans on her any more than she is already, she doesn't think she can take it. And that's not her fault...yes ideally she should choose another method to help, call or tell someone, tell Yura to transfer to her school, etc...but she's a kid, man.
Caregiver Burnout is a big thing. And the inexperienced are so susceptible.
So when Yura (implicitly, your take away may be different) wants Koma to be there when she commits suicide, Koma can't and tries, for the first time, amidst the now drowning pressure, to ask her almost directly to not do it....but it's at just the wrong moment as the door closes (literally). And Yura may literally drown, but so is Koma figuratively with what's just happened.
It's damn good...I kinda want to see if anyone interprets it different.