Karamatsu dies

Day 1

Two a.m. It's two a.m when Karamatsu Matsuno finds himself on the brink of death; he falls over in the family bathroom after trying to pluck his eyebrows and hits his head on the sink, not killing him, but causing a laceration on his forehead. He calls out for help, while bleeding profusely. Does anyone notice? No.
At four a.m, Todomatsu has to pee.

"Choromatsu," he says, tugging on his brother's shirt, "I have to pee." Choromatsu begrudgingly accompanies the younger man.

Karamatsu, by this point, is barely clinging to life.  Todomatsu finally makes it to the bathroom. He really has to pee.
Choromatsu freezes, grabbing Todomatsu's shoulder. "Did you hear that?" He asks, referring to Karamatsu's agonized groans. The younger brother only shrugs him off, saying something along the lines of 'as if' or 'stop playing around'. Either way, he ignores Choromatsu's stupidity.
As he tries to open the bathroom door, it gets caught on something. It's large and heavy enough to hinder its ability to function. Dammit, he thinks, this house is awful. Just like Karamatsu.

He pushes on the door, shoving it with all his might. Choromatsu is asleep on the ground. Totty hears a noise; it's terribly faint, and barely understandable, but he can somewhat make it out.

I'm dying, b r o t h e r
The youngest Matsuno screams, dragging Choromatsu back to their bedroom. Karamatsu remains in the bathroom, bleeding out and alone. He can feel his consciousness fading away.

Finally.
Karamatsu Matsuno is dead.