"Project SEKAI COLORFUL STAGE! feat. Hatsune Miku" added the song "Rabbit Hole" on October 3, 2026. This track is part of the game's "6th Anniversary Song Addition Event," and players can play it in the rhythm game after redeeming it. As the fourth of the 12 tracks added during the event, "Rabbit Hole" continues the daily release schedule, adding another popular title to players' collections.
"Rabbit Hole" was written and composed by DECO*27. The song was first uploaded to niconico, YouTube, and bilibili on May 19, 2023, performed by Hatsune Miku, arranged by tepe, with bass by Shota Horie. Thanks to its distinctive melody and lyrics, the song quickly went viral, surpassing 100 million views on YouTube and earning the status of a VOCALOID Legend. Players can redeem this song in the in-game "Music Shop" using "Music Cards."
The 6th Anniversary Song Addition Event kicks off on September 30 and runs until October 11, with one new track added each day. In addition to "Rabbit Hole," the event features Tatsuya Kitani's anniversary song "Emerald," Kurokuma's high-difficulty track "at," as well as works from other renowned creators such as "Demon Road" and "Darling." For Project SEKAI players, this nearly two-week period of consecutive additions is undoubtedly a great opportunity to expand their song libraries.