Yoshika is from Kouchi Prefecture. When she was younger, she almost drowned after swimming out to sea, giving her aquaphobia. After having awakened to the ability to receive oracles, she selected Koori Chikage, one of the original Heroes. For most of her life, her name was always mispronounced due to having similar writing as "Mika". When she met Chikage, however, she correctly stated her name as Yoshika, and she has held her in high regard ever since.