Kakushinteki Metamorufo-se! (also written as Kakushinteki☆Metamaruphose! or Kakushin-teki Metamarufōze) is the opening theme tune to the Himouto! Umaru-chan anime series. It is performed by Aimi Tanaka, the voice actress of the infamous Umaru Doma.
TV version (Official Sentai Filmworks translation)
UMR! UMR! Not "uma", Umaru! (2x)
Always play with all your strength and spirit!
Enjoy yourself more and more, girl
So that no one notices
Okay, go! Himouto life
Wearing a hood 'cause I feel like it, lounging around again today
With my favorite food, potato chips in hand
Let's have a staring contest with the computer
A Chinese peony when I stand, a tree peony when I sit,
My walking form is a lily flower
A perfect high school girl everyone envies
But look, when I come home I transform! So let's be lazy
Forever the 3-way combo: eat, sleep, play
Always, always, games will be my friends
Big Brother is strict
But he always, always forgives me
Unlimited selfishness is the flip side of love
UMR! UMR! Not "uma," Umaru! (2x)
Alright, the end!