Found by a riverbank when he was a kit with his brother Sparrowkit. Adopted by Dirtfur and had a great kithood until his adopted father disappeared. Later in a clan meeting, he found out that his father was banished. Sunkit stood against Lionstar and believed that the golden leader spread lies and rumors about his father. Because of his behavior, Sunkit’s apprentice ceremony was delayed twice. He was sent to talk to Omenshade (apprentice medicine cat) about his feelings and he was still in denial. 

When his brother was changed to an apprentice this started the dark path he would take. Because Sparrow became an apprentice without him Sun will hate his brother for a short time. Pouting in the nursery Lightpaw tried to comfort him and when discussing his feelings Firehawk intervened and finally made it clear to Sun that he is the one spreading lies and rumors and to not be in denial any more.  

One random day Sun was whisked out of the nursery and thrown at Dirt. Looking around to see Lion and Fawn the tom was confused about why he was there until Lion said he was going to kick him out. But due to the fact that his leader felt merciful and seeing that his once father was ignoring him, Lion gave Sun a second chance.