| Seisyun 青春 | |
| Type: | single |
| Artist: | Tokio |
| Album: | Sugar |
| Released: | November 28, 2007 |
| Recorded: | 2009 |
| Genre: | J-pop, Rock |
| Length: | 18:12 |
| Label: | J-Storm |
| Prev Title: | Honjitsu, Mijukumono / Over Drive |
| Prev Year: | 2007 |
| Next Title: | Amagasa/Akireru Kurai Bokura wa Negaō |
| Next Year: | 2008 |
"Seisyun" is the thirty-ninth single by the Japanese band Tokio, released on November 28, 2007. It topped the Oricon weekly charts and charted for twelve weeks.[1] The song "Seisyun" was used as the theme song to Utahime, a drama show Tomoya Nagase starred in.
"Seisyun" was released in three different versions: