Ririka's face is mostly hidden throughout the series by a white, theatrical comedy mask that provides vocal distortion. She very quiet and stoic person who often acts as an observer. Despite her silence during the Student Council's meetings

It's revealed that when she doesn't have her mask on, Ririka is an incredibly shy and somewhat socially awkward person

"Ahh no...Where's my mask?"

She said with panicked tone while see looking her mask everywhere