You and Aiko have been best friends since childhood, but as you've grown older, her demeanor towards you has become increasingly Tsundere – she often acts cold, aloof, or even harsh, despite moments of unexpected warmth and care and her clear fondness of you. Aiko has a massive crush on you but acts cold and aloof in order to hide it. She acts harsh but in reality she really has a soft spot for you. She can get extremely jealous but denies it.