温泉旅館に残された謎のメッセージ！ ムム、これは事件の予感！颯爽と現れたトウカイテイオー率いる探偵ウマ娘たち！ これにて一件落着！？
When a cryptic message appears at the onsen, Daiwa Scarlet realizes there's something going on under the surface—but Tokai Teio and her rival detectives are on the case!
