Teru is a 14 year old Japanese girl still in junior high and her hero partner is Nvillo, though she calls them Ebio. In the first chapter she manages to save every rider on a broken roller coaster, but since one of the riders, Koishikawa Iko, ends up with critical injuries despite Teru's efforts, many members of the public blamed Shy for her injuries. This sends Teru into a depressive and anxious spiral that leads her unable to transform in Shy for a month, causing the public view of her to gradually grow worse.

The only thing able to finally able to snap out of that mental state is when she comes across a burning hotel building and overhears Koishikawa's little brother demanding that they let him save the people in the building, declaring himself to be Shy. He strongly declared that no matter how scared someone was, as long as you want to save and protect someone, that made you a hero. His words motivated her to transform into Shy again and jump into the building to save the people stuck inside.

(Source: Shy Wiki)