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.
Take this serious--
--اتّخذ الأمر بجدّية
Nimm das gefälligst ernst …
c’est du sérieux.
Prendi la cosa più seria—
Leve isso a sério!
Отнесись серь...