Where's Kachi?

Where's Kachi? is a story of three friends Jelly, Machi and Kachi who are playing hide and seek. All seems well until they can't find Kachi. Jelly and Machi begin to worry when they can't find him. During their search, they come across a cave with a strange noise coming from inside that they've never heard before. What could it be? But more importantly, what happened to Kachi?