Yusuke is an honor student who takes an art course at Kosei High School. He was raised by Madarame as his mother died when he was three. Therefore, he does not remember her and Madarame took great care of him. As he grew up, he was tutored in art by Madarame, with his masterpiece "Sayuri" being one of his greatest inspirations for his artistic career. In reality, Madarame only raised Yusuke for the sole purpose of exhibiting his artwork using his name, and he would often give him meager rations during his tutelage. By the time the game begins, most other pupils in Madarame's shack are cast away, died because of direct or indirect abuse by him, left due to losing interest in art, and Yusuke is the last pupil living in his atelier. While he appears to be aggressively defensive to Madarame, before the events of the game, Natsuhiko Nakanohara asked him about how Madarame treated him, and he admitted that he would leave his shack if he could.

While not directly stated by him, it was heavily implied that Madarame barely treated him as a person as he grew up. He did not bother giving him proper rations, fees or a proper bed, and was always looking to sabotage his artistic career while possible. Despite this, Madarame's great care towards Yusuke had caused him to develop a severe case of Stockholm syndrome that persisted after Madarame's fall, where he still believed that his mentor and adoptive father was a good person by the time he was conceived and wished for him to apologize and reconcile together.

One tragic day, Madarame witnessed Yusuke's mother having a seizure in front of him, and instead of easily offering medical support, he let her die in vain and made duplicates of her last piece dedicated to her son to sell to the public, which granted him the fame and credit he has today. In order to give it "mystery," Madarame altered the art by removing the baby from the painting completely, and that baby is none other than Yusuke himself. Since he was just three years old, Yusuke could not remember the original Sayuri and believed that the defaced Sayuri was its true form.

As Yusuke grew up, he developed artistic talent, which Madarame also took advantage of. Inspired by his control over Yusuke, Madarame decided to start targeting other youths in Tokyo, using them for their artistic ideas and throwing them out of the house, unsupported, if they did not comply with his wishes. None of Madarame's students receive credit or recognition for their works. Yusuke is no exception to this. Madarame uses them to take their credit for his own, just like he did to Yusuke's mother and his disciples, like Natsuhiko, many years ago.

Now knowing the whole truth, Yusuke thanks his former mentor for now giving him no reason to forgive him. Eventually defeating him and stealing his heart, Yusuke retrieves the original Sayuri painting that his mother had painted for him. Yusuke deduces that "Sayuri" is just a made-up title by Madarame for the painting, and unlikely to be his mother's true name for the fear of exposing his scam.

After the exhibition, Madarame confesses to his crimes and is swiftly punished and discredited for it. Yusuke sadly recalls the "happy family" he lived in when Madarame's other disciples were around and how as he grew older, he never lost the hope that they would come back and they all could be happy once again. Now that he is part of the Phantom Thieves, he feels like he has another "happy family" again. Wanting to let go of the past, Yusuke gives the recovered and restored Sayuri painting to the protagonist, who then displays it at Café Leblanc.

Because Yusuke no longer wishes to live with Madarame, Yusuke does not have housing. He wonders where he should go, once staying over at Café Leblanc for a night. However, he eventually decides to find residence at the dormitories of Kosei High School.