嬉しい、楽しい、幸せカーニバル。 (Ureshii, Tanoshii, Shiawase Carnival.)

Background
"Ureshii, Tanoshii, Shiawase Carnival." is an original song composed by Utata-P with GUMI.

This song was uploaded onto Niconico and YouTube on December 17, 2014. It's part of Utata-P's Happiness Series and the sequel to Eien ni Shiawase ni Naru Houhou, Mitsuke Mashita. The song's theme is based around a confusion between the words "carnival" and "cannibalism".