Special Training! Magic Wand! Riko's Sister is the Teacher!?

S1 E6: The next lesson is taught by the teacher Liz, who is an educational intern and Riko's older sister. The content of the lesson is to make a shape with water using a magic wand and then hold the shape for 10 seconds. Riko tries to show off in front of her sister but after failing she quarrels with Liz and runs out of class.