"Ai no Uta" is a Japanese song that featured in commercials for Pikmin 1; a short clip of it can be heard in Pikmin 2 by assembling 20 of each of the 5 colours of Pikmin. The song is sung by the group Strawberry Flower, who also produced the theme song for Pikmin 2. The title of the song translates to Song of Love, so-named because the song expounds on the emotions the Pikmin feel in relation to their involvement in the game, and also their devotion to their given task of helping the game's protagonist, Captain Olimar.
The song itself was released as a CD Single on December 6, 2001 and remained in the top ten for several weeks. Unexpectedly, the song actually outsold the game itself.
These are the first 30 seconds of the song.
Ai no Uta was also a song in Super Smash Bros. Brawl in the stage Distant Planet.