Graduated from being a Bunny-character.

...on that day, U-chan

Of rabbits... I wonder if they taste good... If you extend the final vowel of the first line of the song - 兎追いし /usagi oishi/ - "chasing rabbits" - it becomes 兎美味し - "rabbits are tasty"

Whenever I hear this song, the thoughts just flow in, you know?

I cha~sed after ra~bbits on that mo~unta~in♪ ♬Furusato

Memories of graduation, pyon?

Oh, the graduation song pyon?