The Anthem of the Heart

As a young girl, Jun Naruse was very excitable and talkative. She used to love fairy tales and was always excited about the castle on the hilltop, which in reality was a love hotel.

One day, she saw her father leaving the love hotel. Not realising the significance of it, she exposes her father's infidelity. Her father blames her for the family conflict that follows. While she is crying, she imagines a fairy egg that curses her by sealing her words, so she won't hurt people again.

As a result of her "curse", Jun is not able to speak and suffers stomachaches whenever she tries to speak.

Years later, when Jun is attending high school, her homeroom teacher, Kazuki Jōshima, signs her up as a member of the Community Outreach Event along with three other classmates:

• Takumi Sakagami, a shy member of the computer music researching club
• Natsuki Nitō, a cheerleader and honor student
• Daiki Tasaki, the former ace of the baseball team, who has a broken elbow

When she goes to the committee's room to reject her position, Jun hears Takumi singing and is captivated. She then tells Takumi about her past using her phone, and requests for him to turn her words into a song. In this way, Jun learns that though she cannot speak, the 'curse' doesn’t affect her if she sings. Her class decides to perform a musical for their school festival based on the story of her experience narrated in the form of a fairy tale.

While discussing the musical, Daiki has a falling out with his teammates. Jun intervenes, which leads to another stomachache, but this improves her bonds with the other Committee members. Misunderstanding Takumi's concern for Jun as a sign that he is falling in love with her, Natsuki tells Takumi that she will cheer them on, despite Natsuki's feelings for Takumi.

The next day, Daiki makes amends with his teammates. As they spend time together preparing for the musical, Jun starts to develop feelings for Takumi, while Daiki starts to develop feelings for Jun. Daiki asks Takumi about his relationship with Natsuki, having heard rumors that both of them were dating during middle school, but Takumi denies this since Natsuki had told her classmates that they were not dating when she was asked. Natsuki also tells Daiki that she currently has a boyfriend. On the night before the musical, Takumi asks Natsuki about the boy she's dating currently, leading Natsuki to finally reveal that the boy she's referring to is none other than Takumi himself before she accuses him of falling in love with Jun. Takumi reveals that while he is concerned about Jun, he is not in love with her and he has always regretted not trying to convey his feelings for Natsuki during middle school even when he was aware of her feelings for him at that time. Unbeknownst to them, Jun overhears their conversation. Heartbroken, she runs away and meets the fairy egg, who reveals that she has worsened the curse by trying to convey her feelings for Takumi. Jun doesn't show up on the day of the musical, leaving Natsuki to fill her role while Takumi frantically goes searching for her.

Takumi finds Jun at the love hotel that has been shut down. To his surprise, she can talk normally. Jun angrily lashes out at Takumi as he tells her that the reason she is unable to convey her words is not because of the fairy egg's curse but because of Jun's fear. Wanting to hear her voice once more, Takumi allows Jun to lash out all of her anger and frustration until she is satisfied. Jun confesses her feelings for Takumi, but it is revealed that Takumi is still in love with Natsuki, to which Jun replies that she knew. Takumi then expresses his gratitude for Jun because before he met her, he was unable to say what he truly felt and only went along with everyone else. This convinces Jun to perform in the musical. Jun and Takumi arrive just in time before the final scene, allowing Jun to sing and convey her feelings to her mother who finally understands what she has been through. As the musical ends, Jun realizes that the fairy egg was actually nothing but imagination that she created to have someone she could blame for her condition, and now she decides to open up her heart, coming to terms with her past.

As the movie ends, Takumi and Natsuki reconcile their relationship, while Daiki finally confesses his feelings to Jun.

• Inori Minase as Jun Naruse (成瀬 順, Naruse Jun)
• Kōki Uchiyama as Takumi Sakagami (坂上 拓実, Sakagami Takumi)
• Sora Amamiya as Natsuki Nitō (仁藤 菜月, Nitō Natsuki)
• Yoshimasa Hosoya as Daiki Tasaki (田崎 大樹, Tasaki Daiki)
• Yō Yoshida as Izumi Naruse (成瀬 泉, Naruse Izumi), Jun's mother
• Keiji Fujiwara as Kazuki Jōshima (城嶋 一基, Jōshima Kazuki)
• Kouki Uchiyama as Fairy Egg

Jun Naruse (成瀬 順, Naruse Jun)

Jun is the protagonist. She was originally a very upbeat, cheerful child, but after she exposed her father's unfaithfulness to her mother, she became quiet, timid and unable to speak. She later finds her voice by joining Takumi and the others in making a musical, in which she plays the main character.

Takumi Sakagami (坂上 拓実, Sakagami Takumi)

Takumi is another central character, who like Jun, is also quiet and timid. Like Jun, his parents are divorced, and he lives in the care of his grandparents. He plays piano, and played a major role in helping Jun set up the musical for the Charity Committee.

Daiki Tasaki (田崎 大樹, Tasaki Daiki)

As a member of the school's baseball team, he is initially seen as grumpy and fully rejects the idea of the musical. Through the course of the movie, he learns to warm up to his classmates, and plays a central role in the musical. He also starts to develop feelings for Jun, and eventually confesses his feeling to her.

Natsuki Nitō (仁藤 菜月, Nitō Natsuki)

Takumi's ex-girlfriend, still has feelings for Takumi. Though initially reluctant to join the musical, she warms up, and becomes a close friend of Jun. It is suggested Daiki had feelings for her, though she rejected them.

Fairy Egg

A small mystical being resembling a white egg that only Jun can see. He has a thin mustache, two black dots for eyes, while wearing a tuxedo and a fedora hat with a feather on top. After Jun accepted his request to help her as a child, the Fairy Egg put a curse on her and sealed her mouth closed so that she'll never speak and hurt people ever again. In the end, he is revealed to be a fragment of Jun's imagination. He has a black spot floating around his left hand and when he hides it, he turns into a prince which is a pun with the kanjis of "玉子(tamago=egg)" and "王子(ouji=prince)."

The film was released in theaters in Japan on September 19, 2015.[6] Aniplex of America released the film in North America on November 11 of the same year.[7]

A live-action film adaptation was announced in March 2017.[17] Directed by Naoto Kumzawa, it stars Kyoko Yoshine, Kento Nakajima, Anna Ishii and Ichiro Kan. Filming began in March 2017 in Chichibu, Saitama and the film was released on July 22, 2017.

• Official website (in Japanese)
• Official English website
• The Anthem of the Heart (film) at Anime News Network's encyclopedia
• The Anthem of the Heart at IMDb