Rio Amakusa

Amakusa Rio (天草理緒, Amakusa Rio) is Amakusa Ryou's sister and the best friend of Arima Ichika. Rio invited Ichika at her place when her older brother Amakusa Ryou returns, he is surprised to see Ichika and states that she saved his life today. Rio is interested to know more, however as her phone rings, she goes in the other room to speak with her mom. Returning to them, she is surprised to see Ryou confessing to Ichika.