- "I love my brother, Taiga..More than the world."
- —Yasuko Saejima
Yasuko Saejima first introduces herself by the alias "Lily" after negotiating a loan with Shun Akiyama of Sky. She under orders from Katsuragi to kill Shibata men and the head of Kanemura Enterprise,hoping her desire to see his older brother again,Saejima.
Yakuza 4 Edit
Finance for the sum of one hundred million yen in cash. In order to earn the exorbitant sum she requests, she agrees to go through with Akiyama's test; earn three million yen in three days.
Akiyama take her somewhere to buy the dress for her before Elise club as a hostess at Akiyama's hostess club.
After passing the test, Akiyama calls her to meet up at the rooftop of Millennium Tower for giving her a bag of three million yen. Akiyama explains the true reason that he is not testing her but also testing himself. Akiyama demands to know why She would go killing Shibata Family and Kanemura. Yasuko shocks but refuse to tell Akiyama the reason why and Akiyama let her go in case she return and visit Sky Finance when she pay him back someday.She leaves Akiyama alone.
Yasuko is summoned by Tanimura who demand to know what happen to her and his father the day before his father was killed in twenty years,but they got disturbed by Shibata men who won't Yasuko out from their sights. While Tanimura fights these men,Yasuko run away and later got kidnapped by some Shibata men and bring her to the dock. Shibata ask Yasuko why she killed some of his men and Yasuko said she can't believe she finally got three million yen as Arai raise an eyebrow. Shibata insist to know more,but Arai suggest they have to kill and he will take care of the mess. Shibata refuses and taking off her buttons,staring at her chest/ Shibata mumbles how a man can be seduced by her as he want to touch her skin. Yasuko shocks watching Shibata got shot behind Arai aimed his gun. Yasuko is rescued by Tanimura and take her to his hideout.
Yasuko remain silent when Tanimura explains the hideout got nothing with cops as it safer around. Yasuko asks why would he hide her something. Yasuko explains what happened between her and Tanimura's father back in twenty years and Saejima. She reveals the reason why she killed those is she under orders from Katsugrii who know her brother and give her a freedom if she killed those for him to prove Saejima's innocence. Yasuko realize she get tired of his orders anymore as she give him her a bag of three million yen Akiyama lent her to have return back to him for him. Yasuko plan to head Okinawa to find her brother in private prison alone.
Yasuko arrives to Okinawa,speaking the police about her brother's whereabout but the police always told her that place doesn't exist in Okinawa and wasting their time. She is approached by Kiryu and Hamazaki. They lead her to Tamashi Family's old office. Yasuko learns Hamazaki is Saejima's inmate friend and signs reliving. Yasuko surprise his brother is in Tokyo. They are approached by Saito and his private prison guards. Hamazaki protects Yasuko while Kiryu fight those guards. Hamazaki tells Kiryu to take her to Tokyo.
Yasuko and Kiryu arrive in Kamurocho. Kiryu take her to New Serena to meet Date. Yasuko explains the whole story about her and Saejima front of Kiryu and Date. Yasuko tears but doesn't care if his brother is a killer or not,only the matter that he is her brother that she loves. Kiryu tells Yasuko to stay with Date and he shall find Saejima for her. While Kiryu out looking for Saejma,Yasuko drugs the sleeping pill into the glass to Date as he sip and collapse on the ground,she run leaving New Serena. Yasuko is found by Akiyama and Tanimura and running to Purgatory down the sewer. Yasuko leaves these to Kiryu heading to Purgatory but got hostage by Ueno men. Yasuko and Saejima are taken to Kamurocho Hill.
Kida picks her holding her as negotiate exchange to the notebook Kiryu had. Kiryu holds Yasuko as Kiryu give Kida and walking to Katsuragi . Yasuko look at Kida aim a gun at them. Yasuko look kneeling over the edge to Kida got shot lying the lift down after Arai shot. Yasuko turns release Saejima. Yasuko notices Katsuragi picks his gun behind and shoot Saejima's arm left side. Yasuko rushes as he aim another bullet,saving Sajima got shot her back. Yasuko smiles telling Saeima to wait as she turns walking to him. Yasuko pick his gun that Tanimura gave her back before they fought Kiryu. Yasuko relives that Saejima is innocent but she states she got the blood on her hands then shoot him in the head before collapse. Saejima holds her into arm and yelling her name before she whispers her name softly before she died.