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.
sakaime nai gradation no hazama de "oide"
Im ansteigenden,
grenzenlosen Raum … „Komm.“
Es un espacio degradado sin límites
"Ven"
Es un espacio degradado sin límites
"Ven"
Quelque part entre deux mondes
Elle t’invite à franchir le pas
No espaço gradativo e sem 
fronteiras ela me chama
В градиентном пространстве
нет границ, и меня зовут.