Kaoru, a friend from the piano class Ruli once attended, has gone missing. While searching for her, Ruli and the gang find a strange dent and her shoes. And as they continue their search, Hiro is suddenly asked a mysterious riddle.
and they couldn't answer!
!ولم يستطيعا الإجابة
und sie kannten die Lösung nicht.
et ils n’avaient pas la réponse !
ma non sono riusciti a rispondere!
e eles não conseguiram responder!
но они не отгадали её.