Spring Blossoms is a K.K. Slider song. It first appeared in Animal Crossing: Wild World if the player put an invalid song name. The song reappeared as a secret song in Animal Crossing: City Folk. When the player puts in the song's name, K.K. Slider will talk about a character named June. The music is originally from Cherry Blossoms Festival theme from Dōbutsu no Mori and Dōbutsu no Mori +. None of the villagers have this song.
Trivia It's a secret song. June was a villager. As said above, it's based on the song of the Cherry Blossoms Festival.