A 17-year-old alchemy warrior that was assigned to take care of a homunculus problem in Kazuki's town.
When Kazuki tried to save her from a homunculus (in actuality, she had the situation under control) she felt a sense of attachment to him and revived him with a kakugane, intending to make sure that he never gets killed again. Tokiko is very dedicated to her job, claiming that she hates all homunculi, and quit going to school in order to be more efficient. This hatred comes from the trauma she suffered as a little girl, when all the people in her school were killed or eaten by homunculi except her. As such, she is serious almost all the time, which leads to some awkward situations when with Kazuki and his friends. She is later assigned to be a student at Kazuki's school by Captain Bravo.
Her quote when battling is "I'll rip your guts out." True to her words, the Valkyrie skirt has torn many enemies apart.