Aili is the younger sister of Rei, a master of the Nanto Suichoken style. Her background is marked by profound tragedy that sets the initial stage for her brother's quest for vengeance. On the day that was to be her wedding, her home was invaded by the villain Jagi, who killed her parents and her groom before kidnapping her. Jagi then sold her into slavery, and she was forced to endure a life of servitude and demeaning treatment at the hands of various owners. The psychological trauma from these horrific events was so immense that she could no longer bear to witness the world around her, leading her to seal her own eyes with a medicine or poison, rendering herself blind.

Initially, Aili is portrayed as a deeply passive and fragile individual, broken by her suffering and resigned to her fate. Her blindness serves as a physical manifestation of her psychological state—a refusal to engage with a reality filled with pain. Her primary role in the story is that of a catalyst for her brother Rei's actions; his search for the man with seven scars on his chest, who he learned was responsible for her disappearance, drives a significant part of his character arc. When she is reintroduced into the narrative, she is being held captive by the Fang Clan, who use her as a hostage to force Rei and Kenshiro into a deadly confrontation. It is during this ordeal that Kenshiro saves her, using his knowledge of pressure points to restore her sight.

Aili's key relationships are central to her development. Her bond with her brother Rei is one of deep familial love, and his desperate quest to find and rescue her highlights his devotion. Her gratitude towards Kenshiro, who not only saves her life but also cures her blindness, cements a strong bond of friendship between him and Rei. However, the most significant influence on her personal growth is the young girl Lin. Witnessing Lin's unwavering courage and defiance in the face of oppression from Raoh's forces inspires Aili to shed her previous passivity. She finds the will not only to live but to fight for herself and her community.

This marks her most notable transformation. Aili picks up a crossbow and actively participates in the defense of Mamiya's village, successfully killing several of Raoh's soldiers. This act demonstrates her newfound strength and independence, a stark contrast to the traumatized slave she once was. After Rei dies from the fatal pressure points inflicted upon him by Raoh, Aili continues to live in Mamiya's village, honoring her brother's memory by tending to his grave. In terms of abilities, while she is not a martial artist, she becomes proficient with a crossbow, using it effectively in combat to protect her home and the people she has come to care for. Her journey is one from a victim of unspeakable cruelty to a survivor who finds the strength to protect others.