During attendance day, the Guardians announce that the school will be participating in a choir contest. Amu ends up with the lead part while Marimo is chosen as the pianist. Because Seiichiro is a bad singer, Marimo helps him practice by playing the piano with him, and tells him about her dream to keep playing the piano. During rehearsal, Marimo makes a simple mistake and Saaya and her group criticize Marimo for it. Marimo becomes upset and excuses herself from the rehearsal. The next day during the competition, Marimo does not show up. Because of Saaya's earlier criticism, Marimo's Heart's Egg turns into an X Egg and hatches. The Guardian Characters sense this and the Guardians, along with Seiichiro, go looking for Marimo. With Seiichiro's unwitting help, Amu transforms into Amulet Heart and purifies the X Character. The choir performs successfully, and Amu Character Changes to sing her solo.
Kanae Itou
Amu Hinamori (voice)
Kana Asumi
Ran (voice)
Nanae Kato
Miki (voice)
Aki Toyosaki
Su (voice)
Reiko Takagi
Tadase Hotori (voice)
Kaya Miyake
Kiseki (voice)
Yuichi Nakamura
Ikuto Tsukiyomi (voice)
Miyuki Sawashiro
Yoru (voice)
Nana Mizuki
Utau Hoshina (voice)
Yokote Kumiko
El (voice)
Hiromi Konno
Il (voice)
Saeko Chiba
Nadeshiko Fujisaki (voice)
Ryoka Yuzuki
Temari (voice)
Atsushi Abe
Kūkai Sōma (voice)
Tomoko Nakamura
Yaya Yuiki (voice)
Hiroyuki Yoshino
Daichi (voice)
Sayuri Yahagi
Rima Mashiro (voice)
Sayaka Narita
Kusu Kusu (voice)
Mitsuki Saiga
Kairi Sanjou (voice)
Nobuhiko Okamoto
Musashi (voice)
Junji Majima
Yū Nikaido (voice)
Kimiko Koyama
Pepe (voice)
Rio Natsuki
Yukari Sanjō (voice)
Eri Nakao
Hikaru Ichinomiya
