It doesn't matter where you are, pain always follows you. At first, I thought that life (or unlife) here will be impossible for me. I believed even the slightest mistake might cost me my life. Eventually, however, I met friends, became a high ranking shinigami, and even have a lover now. But even after so many good things, the pain eventually returned. Originally, when I was alive, I couldn't bear it. It broke me. But now? Now I'll embrace it. If someone is suffering, I'll be there to share the pain. As long as others are happy and safe, feeling pain, no matter how much, will be the same as greeting a friend of old.
Every system cracks under a mistake from time to time.
Even the one of the Shinigami, whose legend should be known to everyone.
When a human commits suicide, their soul gets bound to the earth as punishment and they have to keep on living as a Shinigami and collect the souls of the dying.
Like that they are forced day after day to watch people find the peace they longed for so dearly. Hence why it is a cruel fate to be made to live this existence despite just being an unlucky soul.