(Now, I am no experienced guy who knows a lot about Puyo Puyo Tetris, so... I will make some things by myself :P)

You are casually walking in Suzuran (a modern urban city that's the hometown of Maguro, Ringo, Ando and Risukuma) on your way to some destination you probably want to go in this vast city or the Shopping District where Maguro and Ringo live, everything all in thought until... you get boo-ed by a ghost that wants to give you a... a pop quiz?

Yu: Ta-da!! Looks like we have a new, very new participant of this... very, very, very.. gHOSTly pop quiz, hah hah!! With me, Yu and my twin brother, Rei, on our way to turn you into a ghost! She wants you to participate in her pop quizzes, lately, she has been doing this to many unsuspecting people, that flat out refused to join to be a ghost or simply ignored. A cheerful and puny ghost who is constantly silly, with no legs but has human skin.

Rei: .... And with me, Rei of our show... Horror Hour..! At the side of Yu, being quite the opposite in this comedy duo, being quiet and terse and lets her sister do her thing, even joining with her pretty much. His bangs cover his eyes completely with his hand being open in a mellow manner, to that of flying a bit.