The design for Tomomo (Casual) first appeared in 200% Mixed Juice!, although her Sweet Eater design did not. The earliest rendition of the Sweet Eater design first appeared on Hono's Twitter[1] before being added to 100% Orange Juice! two months later.
Sweet Eater is Tomomo's Sweet Gods name, as revealed in 200% Mixed Juice!.
The title of Sweet Eater was once stated to belong to Suguru, the QP Kiss version of Suguri. However, this was either a joke or retconned later by Hono.[2]
Tomomo (Casual) was originally supposed to release as her own character, until Hono requested Fruitbat Factory to give her the Sweet Eater form as well.[3][4]