When she was still young, she is a inertia, timid and a naive girl. She was living her life enjoying it but until she was kidnapped by unknown gang and saw some horrible scenes.
She also knew her mother is the boss emperor after she saving her and died. For her mother place, she become her sucessor to become the new boss emperor of Sky Feder. She was trained under Genjuro Kazanari who is the one suggest Rinne to become the new leader and Raine's friends, while going abroad with Tsukasa who is her uncle.
Rinne succesfully became the new Boss Emperor of Sky Feder in 6-years-old under the name of Rin Shirotama. Rinne met Millay after that, they get along well until Millay infiltrated and take the information about gangs which leads Rinne to a realization of Betrayed. Rinne developed a hatred towards Millay as a traitor, and those who are naive and trust so much in friendships, example Riki. Before she went abroad again, she make up with Riki what she said about him and Rinne trusts Riki very much now.