"Birthday Eve" is a limited edition single by Koda Kumi, 50,000 copies available. It was the second release in her 12 Singles Collection and charted #6 on Oricon, remaining for four weeks.

Birthday Eve is singer-songwriter Kumi Koda's twentieth single and second in her 12 Singles Collection. It charted #6 on the Oricon charts and, despite being limited to only 50,000 copies, remained on the charts for four weeks.

Like the first single in the collection, you, the back cover to the single was a piece to a puzzle, as was the obi strip, which could only be completed by purchasing all twelve singles in the collection.

The song itself was pop and was about planning the following day for her and her boyfriend.

Birthday Eve received positive reviews from both Japanese and North American fans.

Tom wrote in their reviews how it appeared that Kumi had "borrowed some parts from Diamonds Are a Girl's Best Friend by Marilyn Monroe" in the music video, but how the artist still made the theme her own.

Benii, however, said that with Koda Kumi having a "cool image," it was "discomforting" to see a "cute image that [they] haven't seen before." However, they still gave it a positive review, saying it was a "nice birthday song."

Unlike the first single in the collection, Birthday Eve was not part of a story line.

The music video depicted Kumi as a girlfriend getting ready for the evening, where she would go out to celebrate her boyfriend's birthday and how they would spoil each other. During the video, an homage to Marilyn Monroe's Diamonds Are a Girl's Best Friend with Kumi donning a pink dress as she walks down a flight of stairs with several men in wrestling masks and tuxedos.

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Wikipedia