She's a member of the Horticulture club, who loves plants and looked after the sweet potatoes more than anybody. She tried to use an incantation on member Tomoo, who was teasing her calling her "potato-girl", but in her anger, after hearing him making a bad comment about her, messed up the name she had written on the sweet potato patch, going from “ASATSUMA TOMOO” to “SATSUMA IMO” (which means sweet potato), and inadvertently cursed the sweet potatoes and got her shadow become potato-shaped a price. She quit the Horticulture Club right after.
When the club discover their sweet potatoes having been cursed, Rinne is called into action and he figures Imoto was responsible. She was however too upset and wouldn’t cooperate, but Rinne made her and Tomoo come to the sweet potato patch, and it is revealed that she was in love with Tomoo and was trying to cast a love charm on him. But her anger not only messed up the name she had written but also translated the spell into a curse over the potatoes. The curse would be lifted when Tomoo admitted he liked her, and her shadow turned back to normal. She re-joined the Horticulture Club.