"Dareka no Negai ga Kanau Koro" (誰かの願いが叶うころ?, lit. "When Someone's Wish Comes True") is Hikaru Utada's 13th Japanese-language single (15th overall) and her 1st and only Japanese single for 2004. She released 2 versions of Dareka no Negai ga Kanau Koro: CD and DVD. It was released on April 2, 2004. Dareka no Negai ga Kanau Koro is also included in the "Our Last Days" - "Casshern" OST as the theme song. Dareka no Negai ga Kanau Koro debuted at #1 on the Oricon chart with 150,020 copies sold, became her sixth single to go #1 for two consecutive weeks, and went on to sell 365,000. It was performed on Music Station and on her Utada United 2006 tour. The single reached #1 on Oricon and charted for 22 weeks. This song became the #14 song of 2004 in Japan.
A music box shown at the beginning of the single's promotional video is playing the "Blue Danube Waltz".
The single's promotional video is the first to show Utada playing an instrument, the piano, as she sings. She was credited for playing the acoustic piano in the song in the single's booklet and also in the Ultra Blue booklet, although she has not played any instruments on her live performances of "Dareka no Negai ga Kanau Koro". (She can also play the guitar; this is shown in the video for "Keep Tryin'," and she has also performed "Devil Inside" while playing the guitar.)