Kuro

A tall and skinny black wolf who has a British accent and had lost his memories but he did remember that he was in love with an unknown monster, as a result he began his new life without his memories as a painter and poet. He saw a white monster similar to him, he regained a memory of having a sister, Shiro. He finds her but other than that no other memories have come to him.
After a while his memories came back to him... he was in an accident. Kuro remembered in his youth growing up with his twin sister Shiro in an orphanage and as they grew older she disappeared, he aspired to be a creative artist! But that life wasn't easy... he lived alone with little money to help a freelance artist like himself. Eventually while walking the streets of Snowdin, he bumped into a hyena who found love at first sight. They fell in love and moved in together, they were even engaged! On their anniversary they travelled up to a certain spot in the woods and a great quake broke the ground below them... his lover fell and he came down after her but it was too late. He never knew what happened to her but next thing he knew, he was in the hospital.
He was distraught with his newfound past and the voice of Bonnie haunted him. He met a wonderful man named Carter who confessed his feelings towards Kuro near Bonnie and his anniversary unknowingly. Kuro was hesitant to jump into a relationship but the spirit of Bonnie herself told him to move on and be with Carter and be happy once again.

(NG)
He was married to Carter and longed for having a child... they ended up sending in sperm to a unknown womb and had their child whom they named Grayson.