As the younger half of the "Psycho Sisters," Riku stands out for her fierce and aggressive nature, never backing down from a fight. She positions herself as the leader of the duo, basing this declaration on her perceived intelligence, which she believes surpasses that of her sister, Riko. Riku excels at strategic thinking, crafting plans and carefully assessing situations to ensure the best possible outcome for her and her sibling, embodying a pragmatic approach to their chaotic lifestyle.