ED - Marutsuke (まるつけ)

Source: Crunchyroll
Loneliness is a weapon
It can hurt people
And can make you not realize it
Loving someone is a sickness
It makes it hard to breathe
And there's no cure for it
These days are a miracle
But something's still missing
There's still an empty column
You're mysterious
Your existence
Makes me both stronger and weaker
I wonder how we're doing
Are we being proper human beings?
I'm not sure
But I check our answers as I try to find out