Rio Amakusa

Rio Amakusa (天草 理緒, Amakusa Rio) is the younger sister of Ryō Amakusa and the best friend of Ichika Arima.

Appearance
Rio is a 17-year-old high school student with long blonde hair that reaches her chest. Moreover, she has hazel-colored eyes and a petite body type.

Like her friend, she also wears the school uniform of a blue blazer, gray sweater, light blue button-up, and green skirt.

Plot
Rio invites Ichika Arima at her place. When her older brother Ryō Amakusa 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, he goes in the other room to speak with her mom. Returning to them, she is surprised to see Ryō confessing to Ichika.

For a week, Ryō keeps asking Rio to give chocolate and other presents to Ichika, but as he wants to give her a rose, Rio gets annoyed and gives Ichika's address. At school, Rio is surprised that Ichika did receive a rose from him. She explains that she never had seen her brother like this before and suggests Ichika actually to start to date him. She comments that he is beautiful, has money and good job, but silently whispers he is scum. She tells Ichika, she needs to complain to him about the flower and chocolates, as otherwise he won't stop, but secretly plans Ryō to get Ichika's phone number from this. She gives his phone number and tells Ichika to call him after work.

Relationships

 * Best friend: Ichika Arima
 * Brother: Ryō Amakusa
 * Father: Zenji Amakusa
 * Mother Yoshino Amakusa

Etymology

 * The name Rio means "reason, logic" (理) (ri) and "thread" (緒) (o).
 * Rio's surname Amakusa means "heaven/heavenly, sky, imperial" (天) (ama) and "grass, herb, weed" (草) (kusa).