Hotaru is the reincarnation of the Princess of Saturn, and transforms into the Melancholic Fighter, Sailor Saturn. Hotaru is an isolated, lonely girl who has no friends, and is enrolled as Mugen Gauken Academy in the sixth grade. She possesses a unique power of healing which has alienated her from her peers due to their fear and misunderstanding. Hotaru also possesses the ability to create an enormous amount of energy that can blast anything from her path, but she does this subconsciously. Hotaru's mother died when she was young, and thus she lives in seclusion with her evil father, Professor Tomoe. At first her father had a good heart, but he sold his soul to an entity known as Mistress Nine after the lab explosion killed Hotaru. In return for his soul, the entity allowed Hotaru to live. Hotaru later becomes friends with Chibi-Usa and with the Sailor Scouts. Sailor Saturn is the leader of the Outer Senshi. She is arguably the most powerful of all the Sailor Scouts, but she is severely limited by her weak constitution. As Hotaru, she is a caring and gentle soul, but as Sailor Saturn she has the power to completely destroy entities, fortresses, and entire worlds.