The name for this is Watashitachi no Shiawase na Jikan and here's a brief summary which I copied and pasted for you all.
"A pianist who attempted suicide 3 times, Juri, is taken to help her aunt at a prison where murderers who killed indiscriminately are sentenced to death. There, she meets a man named Yuu who took the lives of 3 people. A mother's antagonism--a brother's death... Together they embrace the violent rebellion in their hearts caused by the large, deep scars they carry.However, before long, they both embrace an earnest hope in their hearts."
Girlfriend liked it, hope you all as well.
