The butterfly symbolizes freedom and transformation, and the cherry flowers symbolize the "carpe diem", living every moment as if it was the nicest and the last: cherry flowers actually have a very short life, but while blooming very few things can match their beauty.
A curiosity: this philosophy of living every moment without fears, caring not for death either, totally, is also at the basis of bushido, the codex of samurais, who often used the cherry flowers as their symbol on account of this.