A sister type. She forgives and is violated as requested. Aika Nagano

The movie revolves around Aika Nagano, who forgives and is violated as requested, indicating a complex and potentially abusive relationship dynamic. The story seems to explore themes of consent, boundaries, and power imbalance, with Aika and Tomoya navigating their interactions amidst a backdrop of emotional turmoil and physical intimacy. As the title suggests, Aika's character embodies a 'sister-type' persona, which may be significant in understanding her role and relationships within the narrative.