Kaeru Batake DE Tsukamaete Portable

Sugano Fuu and two of her schoolmates — upperclassman Norizuki and classmate Hirose — agree to investigate the Seven Mysteries of Tsukiyado as a club activity, mostly to pass the time. At the school's old shrine they also find Hamura and Kuga, two people they barely know. The shrine door is rusted shut, but when they force it open, it crumbles — and inside is something none of them can identify. They throw it away as fast as they can, smoke pours out, and before anyone fully registers what happened, all five of them have been transformed into frogs.