- Shuuji to Akira is the temporary duo formed between fellow JE artists Kamenashi Kazuya from KAT-TUN and Yamashita Tomohisa from NEWS.
- The song was used as the theme song for their 2005 autumn drama, Nobuta wo Produce. Shuuji and Akira are the characters that Kamenashi and Yamashita portray in the drama, respectively.
- Colorful is sung by Yamashita, and was the insert song for his 2005 summer drama, Dragon Zakura.
- Kizuna is sung by Kamenashi, and was the insert song for his 2005 winter drama, Gokusen 2.
- The Limited Edition comes with a special 12-page booklet.
- The single debuted at #1, selling 520,000+ copies in its first week.
- The single surpassed 1 million copies in less than 4 weeks, and became the #1 best-selling single of 2005. The single continued to chart in 2006, and was the #3 best-selling single of 2006.