Tabidachi no Hi ni

Tabidachi no Hi ni (旅立ちの日に) is an ending-credits song from Episode 26 of Nichijou performed by Yukko, Mio, Mai, Nano, Hakase and Sakamoto.

Creation of song
Noboru Kojima, who was principal of Kagemori Junior High School, located in city of Chichibu, Saitama Prefecture, wanted to make his troublesome school better. So he decided to make it a "Singing school" (「歌声の響く学校」), and assisted in creation of a chorus. At first, student resisted that idea, but as a result of persistent efforts of school's music teacher, Hiromi Sakamoto, school became brighter due to the joy of singing.

In late February 1991, Sakamoto asked Kojima to write lyrics for the song for graduates. At first principal refused, but the next day lyrics were placed on Sakamoto's desk. Sakamoto was impressed by the lyrics written by principal, and during one of her breaks she composed the song, which took approximately 15 minutes.

The completed song was sung for the first time as a surprise at farewell party for third-year students by school's faculty. This year, Kojima retired after 41 years working in school, so this was the first and last time he performed. This performance was intended to be the only one, but the following year, students also sung that song.

The popularity of the song spread, and since it has become a classic graduation song in Japan.