St. Thrash is a part of the Underworld. It is a music festival known predominately for its way of showcasing a smorgasbord of heavy metal acts, whether it be one-man bands or otherwise. The musicians themselves are free to roam and hang around these parts without consent. The founder of St. Thrash is none other than Hotaru Obata, who is also the beloved father of Sakiko Obata. The festival's building's structure bears resemblance to a fortress, and an elaborate, but even demented one at that.