Idol × Warrior Miracle Tunes! - Season 1 Episode 22 Let's Get Kojiro Back!

Kanon receives a ransom note during Miracle²'s handshake event demanding the Sound Jewel Case in exchange for Kojiro, though Kojiro escapes on his own. She secretly takes the Sound Jewel Case to the Dokudoku-dan. The Dokudoku-dan turn a construction worker (Kanji Tsuda) into the Negative Jeweler, Hofukuzettoka, and steal the Sound Jewel Case, but the rest of the girls come to her rescue. Miracle Tunes takes the Sound Jewel Case back uses the Rock Jewel to tune up Hofukuzettoka, recovering the Metal Jewel.