Gunjō (song)

"Gunjō"
Single by Yoasobi
from the EP The Book
LanguageJapanese
English title"Blue"
ReleasedSeptember 1, 2020
GenreJ-pop
Length4:08
LabelSony Japan
Songwriter(s)Ayase
Producer(s)Ayase
Yoasobi singles chronology
"Tabun"
(2020)
"Gunjō"
(2020)
"Haruka"
(2020)
Music video
"Gunjō" on YouTube
"Blue" on YouTube

"Gunjō" (群青, lit. "Ultramarine") is a song by Japanese duo Yoasobi, featuring an uncredited chorus by cover group Plusonica, from their debut EP, The Book (2021). It was released as a single through Sony Music Entertainment Japan on September 1, 2020. Inspired by Tsubasa Yamaguchi's manga Blue Period and based on a story text Ao o Mikata ni, the song is described as "a cheering song that inspires listeners by immersing themselves in what they like and expressing what they see."

The music video was uploaded on December 1, and surpassed 100 million views on May 30, 2022. The English version, titled "Blue", was released on October 29, 2021. "Gunjō" was certified diamond by the Recording Industry Association of Japan (RIAJ) after surpassing 500 million streams in the country, the duo's second song after "Yoru ni Kakeru".