Butter-Fly

"Butter-Fly"
Song
A-side	"Butter-Fly"
B-side	"Seven"

"Butter-Fly"
Song
A-side	"Butter-Fly ~Strong Version~"
B-side	"Seven ~10th Memorial Version~"

"Butter-Fly" is the debut single by Japanese vocalist Kōji Wada. It is best known as the opening theme song to the Digimon Adventure anime, debuting on April 23, 1999, as well as the closing theme to the associated film of the same name, originally released on March 10, 1999.

Wada performed two additional versions of the song in the years after Digimon Adventure. "Butter-Fly ~Strong Version~" was released on April 22, 2009 to commemorate the 10th anniversary of the Digimon franchise as well as the 10th anniversary of the release of his initial single. "Butter-Fly ~tri. Version~" was performed by Wada as the theme song for the anime film series Digimon Adventure tri., and was released a few months before he died in April 2016. A fourth version based on the "~tri. Version~" release was produced as the closing credits theme for the final Digimon Adventure tri. film in 2018; this version was performed by AiM, Ayumi Miyazaki, and the eighteen main cast members of tri., and also featured posthumous archive audio of Wada.

The song has also been covered by Masaaki Endoh in his album Enson, and is a recurring feature of the Kumikyoku Nico Nico Douga anime theme mashup songs.

Track listing

All songs arranged by Cher Watanabe.

No.	Title	Writer(s)	Length
1.	"Butter-Fly"	Hidenori Chiwata	4:18
2.	"Seven"	Kouhei Koyama	4:17
3.	"Butter-Fly" (Original Karaoke)		4:18
4.	"Seven" (Original Karaoke)		4:17
Total length:			17:12

"Butter-Fly ~Strong Version~" single

No.	Title	Writer(s)	Length
1.	"Butter-Fly ~Strong Version~"	Hidenori Chiwata	4:30
2.	"Seven ~10th Memorial Version~"	Kouhei Koyama	4:37
3.	"Butter-Fly ~Strong Version~" (Original Karaoke)		4:30
4.	"Seven ~10th Memorial Version~" (Original Karaoke)		4:37
Total length:			18:13

"Butter-Fly ~tri. Version~" single

No.	Title	Writer(s)	Length
1.	"Butter-Fly ~tri. Version~"	Hidenori Chiwata	3:45
2.	"Butter-Fly ~tri. Version~" (Original Karaoke)		3:45
Total length:			7:30