2006 brought another succesful Finnish-Japanese co-production. It seems the Leekspin followed the path paved by Muumi in Japan in the 1990s.
The music is a 1930s Finnish song called Ievan Polkka, performed by the Finnish band Loituma. It is completed by a popular manga anime featuring Orihime Inoue from the Bleach series.
And of course there's a lot on YouTube: Ievan Polkka unplugged, Loituma dance, a cheap fake, an accelerating version, the commercial Jamba ringtone version, a home video and finally the real thing.
UPDATE: Check out Pippi Långstrump med purjolöken.