"Itsuka kitto…" is the debut single by Atsushi, the lead singer of the popular Japanese band Exile. It was released on September 24, 2011 as a "double A-side" along with Exile's 36th single called Rising Sun / Itsuka kitto… (Rising Sun / いつかきっと…). The single debuted at #1 on the RIAJ's Digital Tracks Chart and #1 on the Oricon Charts with first-week physical sales of 234,846. "Itsuka Kitto" has also gained popularity as the theme song for the TV Asahi drama, “Hi wa Mata Noboru“ . The song was written by Atsushi Sato, Matthew Tishler and Andrew Ang.