Her name seems to be affiliated to a Type of Gun.
While returning to Tazmily Village from Alec's house in the mountains, Hinawa gets attacked by a Mecha Drago. Afterwards, Bronson finds her dead, (with the drago fang peireced through her heart) and Flint and Claus swear revenge on the Mecha Drago, resulting in the rest of the story unfolding. She next appears in Chapter 6, when Lucas and Boney chase her ghost through a flower field. She appears in a dream of Alec's, and tells him to put hay on a certain spot. That spot was where Lucas and Boney land. She also appears in the final boss battle as a Voice and Disrupts both Lucas and the Masked Man during their fight.