Aika is cute and a kind older sister. She cares for her family, so she tends to worry about Maika's social life because of her scary eyes. This was seen when she met her friends and coworkers who came to visit her after she was sick and she took pictures of them to celebrate her growing social circle. Her care for her sister has been shown many times as she tries to help whenever she can. When Maika began to cry, Aika attacked Dino whom she blamed for her sister's sadness only to stop after it was another source and apologize immediately.
(Source: Blend S Wiki)