She's gone again.
That's okay, because she'll come back.
She always does. No matter how much I yell.
Bash my fist into the wall.
Almost drawing blood from the one person I vowed never to.
She can't possibly forget those could she?
How could I be so stupid.
The nightmares get so bad at times.
I can't even think straight.
Haunted by everything that I've done.
Only to take it out on her time and time again.
She says she will always forgive me.
And she comes back to me.
Where my sight has failed me.
My ears pick up what I have lost.
I don't hear laughs anymore.
But to my face, she puts on a smile.
Deep down I know I'm a monster.
I can't be healthy for her.
I just want her to be happy.
Maybe this wasn't meant to be after all.
Based off a head canon I had a while ago, in which Mamoru and Haruka do end up getting married, but their happiness is only on the surface.
Their marriage is really rocky and dysfunctional, Mamoru is haunted by his past, and starts to go senile, and developed an anger problem. He wakes up from nightmares in a bloody rage, and has physically hurt Haruka multiple times unintentionally. Haruka knows it's not intentional but it wears down on her, and she can't handle it. So she walks out on him a few times, but always makes her way back to him because she can't imagine life without him in it, but she knows she won't be happy all the time no matter what.
She also knows that without her, Mamoru wouldn't be able to hold his composure nor stay a sane man. He's not only devoted to her, he needs her to prevent him from going completely insane.