When Father was alive as a human gave birth to Chisa and then some number of years later he died and joined the Reaper's Game. Perhaps a bit before but definitely during the Reaper's Game his trans egg began to crack. He survived the Game but was unable to bring himself to return to life, partially because he was conflicted about his gender identity and what it would mean to go back to life. To potentially lose that part of himself, or to regain it but maybe hide it if he wasn't accepted. Since he was unable to even say the words he wanted to be resurrected, the Composer took the decision away from him, and gave him the option to become a Reaper or be Erased.

He bitterly chose to become a Reaper, not wanting to give up, but his spirit was crushed, blaming both himself and the Composer for being unable to return to his family. He felt he was a failure, and the feeling only compounded after an Incident that resulted in Chisa's Soul being lost to the Void from his fingertips, which meant no one except the Reapers and the Composer even remembered her existence.

Time passed and by the time he Ascended to become an Angel he had almost fully transitioned and embraced himself as a man. Accepting the position as a "Father" gave him another chance and began to heal him. More time passed and his former Composer, Null, surprised him with a visit with a special guest - Father's own daughter, Chisa, rescued from the Void.

Null told Chisa nothing about him, believing it was best for Father to handle the situation. It absolutely scared him and took a bit of time for him to not overdo it to have Chisa accept him. It takes Chisa time to get used to her new father but she still loves him and is so happy to see him once again, as who he truly is.

Even is he likes cats a little too much.