is a song by Japanese singer-songwriter Lilas Ikuta from her second studio album Laugh (2025). It was released as a single on April 7, 2025, through Echoes and Sony Music Entertainment Japan. "Koikaze" served as the theme song for Abema's dating reality show ', the third song recorded for the show.
Commercially, "Koikaze" reached number 19 on the Billboard Japan Hot 100 and number 21 on the Oricon Combined Singles Chart, and was certified platinum for streaming by the Recording Industry Association of Japan (RIAJ). The song won the Excellent Work Award and was nominated for the Grand Prix at the 67th Japan Record Awards. Its accompanying music video, directed by Tsukumi Matsunaga and starring actress Kiara Nakanishi, premiered on June 9.
In 2021, Lilas Ikuta's "Romance no Yakusoku" featured as a theme for the Sunflower edition of Abema's dating reality show '. The next year, she performed the original song "Sparkle" for the show's Mikan and Graduation 2022 editions. About three years later, on March 25, 2025, Abema announced that Ikuta's song "Koikaze" would serve as a theme for the New Zealand edition of Kyà Â, Suki ni Narimashita, as well as The First Takes live version of "Sparkle" as an insert song. It was available to digital music and streaming platforms on April 7, alongside "Sparkle" (from The First Take), in conjunction with the first episode of the show premiere. The song was later included on the singer's second studio album Laugh.
"Koikaze" evokes the arrival of spring and expresses the protagonist's tender emotions from falling in love and caring for someone who loves, comparing it to a gentle breeze. The song talks about confusion and conflict that come when a new relationship begins, before ultimately deciding to be honest about the protagonist's feelings.
A special music video for "Koikaze" was uploaded on May 19, 2025, featuring footage from Kyà Â, Suki ni Narimashita: New Zealand Edition, which aired in April. Afterwards, the official music video premiered later on June 9. Directed by Tsukumi Matsunaga and starring actress Kiara Nakanishi, the dreamy visuals capture an emotional transformation of the protagonist as she falls in love.
Ikuta debuted the live performance of "Koikaze" at FNS Music Festival Summer on July 2, 2025. She later performed the song at Best Hits Kayosai on November 13, CDTV Live! Live! Christmas Love Song Fes. on December 15, and ' on December 20, Music Station Super Live 2025 and The First Take with pianist on December 26, the 67th Japan Record Awards on December 30, and the 76th edition of KÃ Âhaku Uta Gassen on December 31.