"Happy Day, Summer Day" 的歌詞如下：
Happy day, summer day
Sunshine and blue sky
Going to the beach, swimming in the sea
With my friends, we're having fun
Laughing and singing together
Memories that will last forever
Under the sun, feeling the heat
This is the best day of my life
Happy day, summer day
Jungle fun, splashing in puddles
Playing in the park, jumping on the trampoline
With my family, we're having a blast
Taking photos, laughing and joking
Memories that will last forever
Under the sun, feeling the breeze
This is the best day of my life
重複副歌部分，直到歌曲結束。