Kaoru has Xeroderma Pigmentosum (XP), and is not allowed to be exposed to sunlight. She sleeps during the day and is active at night. She busks every night in front of a station playing guitar. Outside her bedroom window, she spots a high school boy with a surfboard. She watches him and his friends visit the ocean every morning, before going to sleep. One day, she introduces herself to him without letting him know about her illness. He is Kōji Fujishiro (Takashi Tsukamoto) When her friend drags her home, they sit by her window while they watch Kōji meet his friends. Kaoru explains everything, and her friend notes that she probably goes to the same school as him, and offers to spy on him for her.
The next evening she sits by the bus stop. Kōji arrives on his scooter. Both embarrassed, they start talking and Kōji eventually promises to meet her and listen to her sing another night, at the start of the school holidays. When they meet up, another obnoxious street performer has taken her spot. Kōji decides to take her to the city, where after seeing the sights, she starts playing in a square. (YUI's music video Skyline features this event). A substantial crowd gathers to hear her sing. Afterwards they watch the ocean, and Kōji asks her out.
Their date, however, ends abruptly as the sun breaks out and Kaoru flees home. Kōji is soon informed of Kaoru's condition and is taken aback. For a while, Kaoru stubbornly refuses to see him. Kōji learns of a recording studio where Kaoru could record her debut single, and takes up small jobs to earn the money to pay for it. Her father, out of concern, invites Kōji over one night. At dinner, Kōji reveals his plans for Kaoru's CD. As they walk home that night, the two begin to talk and Kaoru slowly realizes how much Kōji truly cares for her.
As her disease worsens, she loses feeling in her hands and is unable to play guitar. She assures Kōji that she still has her voice.
In the studio, she asks her family and friends to leave. She asks them to wait for the CD.
Time passes. As promised, Kōji brings Kaoru to the beach to watch him surf. The protective suit she had left hanging for years is finally used. By now she is in a wheelchair. She complains that the suit is getting hot. With a painful expression that fades quickly, Kaoru's father tries to convince her that if she takes off the suit, it can't bother her anymore, that she could run around freely. She declines. With that, she struggles to stand up and limps weakly toward Kōji. As she walks, she trips over the sand and Kōji rushes to catch her. She catches herself at the last minute, revealing that it was a feint and giggles at his surprised face.
Finally Kaoru is laid to rest in a coffin full of sunflowers. Kōji, Kaoru's friends and family listen as Kaoru's CD is finally released. In the final scene, Kōji rushes towards the waves, his mind replaying her voice.Yui (singer) - Kaoru AmaneTakashi Tsukamoto - Koji FujishiroKuniko Asagi - Yuki Amane (Kaoru's mother)Goro Kishitani - Ken Amane (Kaoru's father)Airi Toriyama - Misaki Matsumae (Kaoru's best friend)Eri FuseGaku HamadaTakashi KobayashiMagySogen Tanaka - Haruo KatoTitle: タイヨウのうたTitle (romaji): Taiyō no UtaAlso known as: A Song of the Sun (The Sun's Song), Midnight Sun, A Song to the SunGenre: Romance, Human DramaTheme song: Good-bye Days by Yui.Insert song: Skyline by Yui.Insert song: It's happy line by Yui.
There are two Japanese DVD releases of Taiyō no uta, a standard and a premium edition. The premium edition includes a bonus disc with nearly 90 minutes of making-of footage, deleted scenes, the music video for the song "Good-bye Days", and interviews with Yui, Takashi Tsukamoto and the film's director. It also has special features of Yui's Diary and a pick pendant with a necklace. Only making of Taiyō no Uta was released on June 2, 2006. Both standard edition and premium edition were released on June 11, 2006. Midnight Sun has also been released on DVD in Hong Kong, Taiwan and Singapore. The film's original soundtrack is available on CD.
In May, 2015 the writer Eric Kirsten confirmed an American version of the film, centers on New York City. The main couple will be starring by Bella Thorne as Katie (originally Kaoru) and Patrick Schwarzenegger as Charlie (originally Koji). The recordings started in August and the film will be released in 2016.