Rika Hayase

Rika is the youngest member of the Hayase household — a bright-eyed kindergartener whose innocent curiosity belies a surprisingly sharp sense of observation. She anchors the story's present-day domestic scenes with warmth and liveliness. Her most pivotal moment comes in Episode 8, when she accidentally witnesses her older sister Mari vanishing in what appears to be a time-leap. Without hesitation, she reports what she saw to their mother Akira — a seemingly small act that sets off a chain of events, prompting the family to uncover the truth behind their father's secretive research and drawing them into the unfolding crisis.