"Amagasa" (雨傘, "Rain Umbrella") is a song by Japanese band Tokio. It was one of the two A-sides that composed the band's 39th single, along with the song "Akireru Kurai Bokura wa Negaō". The single was released on September 3, 2008, and was their first release with J Storm. "Amagasa" was written by Japanese rock musician Ringo Sheena. In 2014, Sheena covered the two songs she wrote for the single, "Amagasa" and "Kachū no Otoko", for her album Gyakuyunyū: Kōwankyoku.

Tokio's 2006 single "Sorafune" was a hit, being certified by the RIAJ for 1,000,000 ringtone downloads. The song was written by Japanese singer-songwriter Miyuki Nakajima, and acted as the theme song for the drama My Boss My Hero, starring Tomoya Nagase. Since then, Tokio has had several singles written by musicians famous in their own right, such as "Hikari no Machi" by Yoshihiro Kai, another song by Miyuki Nakajima called "Honjitsu, Mijukumono" and "Seisyun", which was written by Tsuyoshi Nagabuchi.

Ringo Sheena had previously worked with musicians Ryōko Hirosue and Rie Tomosaka between 1998 and 2000, writing and producing music for them. This single was the first time in eight years that she had written music for another musical act. "Amagasa" / "Akireru Kurai Bokura wa Negaō" was Tokio's first single released under J Storm. From their debut in 1994 until 2001, Tokio had worked with Sony Music Entertainment Japan, before moving to Universal Music Japan with the single "Doitsu mo Koitsu mo" / "Boku no Mirai" (2001).

...
Wikipedia