Nana Shimura/Relationships

Kotaro Shimura
Despite the little time the two are seen together, Nana loved her son Kotaro very much and cared for him. However, after her husband was murdered, Nana did not want her son to have the same fate, so, much to her dismay, she sent her son away from the world of heroes, leaving him in the care of a foster family so as to prevent All For One from tracking him.

Nana even asked Gran Torino and Toshinori to, under any circumstances, never come into contact with him, preventing her close friends and allies from searching for him before her own death.

Unfortunately for Nana, her actions would ultimately cause her son to resent and detest her legacy for the rest of his life. Kotaro would consider his own mother as a demon, believing she put up her own son for adoption due to putting her duties as a hero before her family. While he would later go on to have a family of his own, he was abusive towards his son, Tenko, and frequently abused him whenever he talked about heroes or her in general. The abuse ultimately drove Tenko to murder his father and his whole family, thereby making Nana indirectly responsible for Tenko becoming Tomura Shigaraki. Later, in the world of One For All, Nana admits to Izuku that abandoning Kotaro was the worst decision she ever made.

Tomura Shigaraki
Years after her death she would meet her grandson when he tried to steal One for All from Izuku. When in the mindscape, he told her right to her face that he hated her. Later, during a meeting between One For All users, Nana asks Izuku if he could kill Tomura. Nana has shown to acknowledge that her grandson ending up on the path of villainy was a by-product of her actions as a mother, becoming emotional in the process.

Despite her remorse towards Tomura, Nana also realizes the evil and destructive being that he has become and states that there will be no stopping him should the villain reach his peak of power. Nana ends up desperately asking Izuku if he would attempt to stop Tomura at all costs, even if it meant killing him. Nana is shocked after Izuku states that he could feel a child crying for help within Tomura, and follows by saying that he will make an attempt to save him, before stating that One For All is a power to save people and not kill. Nana ends up in tears as she realizes that she made the wrong choice in giving up her son.

Sorahiko Torino
Sorahiko and Nana were close allies and friends. She trusted him enough to tell him about the One For All, as well as to entrust him with the training of her successor: Toshinori Yagi. When the three tried to fight All For One, Nana sacrificed her life to allow them to escape, entrusting the safety of Toshinori to him.

Sorahiko became a teacher in U.A. High School in order to train Toshinori solely because of the promise he had made to her.

Toshinori Yagi
Nana was Toshinori's mentor and his predecessor, the seventh inheritor of the One For All Quirk. Nana was the one who told Toshinori that a true hero should smile no matter what, to reassure the people and to not only protect their lives, but also their hearts. Toshinori greatly respected her as a mentor, friend, and hero, to the point that he began to consider her as his own mother.

To the very end of her life Nana showed complete and total faith in her disciple, as in her last moments she she smiles confidently telling him that Toshinari will be the one to defeat him one day, because he is even crazier than All For One himself.

All Might became enraged when All For One badmouthed her and was distraught when it was revealed that Tomura is Nana's grandson.

He still mourns her death even now and after learning that Tomura is her grandson, becomes devastated and first wants to track Tomura down, though Gran Torino convinces him that he's still a villain and needs to be treated as such.

Toshinori finds likenesses of Nana in Inko Midoriya, the mother of Izuku.

Izuku Midoriya
Long after her death, Nana learnt of Izuku being Toshinori's successor. When Tomura and All For One attempted to steal One For All from Izuku, Nana and Yoichi Shigaraki thwarted the villains. Later, when Izuku is recovering from coma, he has a meeting with Nana and the past One For All users. Nana suggests Izuku to kill her grandson Tomura. She is upset over forcing her failures onto Izuku but warns him that some villains just can't be saved at all. Izuku replies that One For All is meant to save people, not just kill All For One. He tells Nana that he wishes to save Tomura, but if there is no choice, he will kill him for good. Nana starts crying at Izuku's answer and agrees to support him. She is later shown to share concern with the other One For All wielders over Izuku's extreme workaholism, worried that he took her words too seriously.

All For One
As one of the inheritors of One For All, Nana was destined to fight against All For One. She considered him a cruel and manipulative person, who scoffing irrationally at the people who just want to live their lives. Along with Gran Torino and All Might, she tried to stop him, but was killed by All For One in battle while letting All Might and Gran Torino escape.

For All For One, Nana was a pitiful woman. He mocks her commitment to ideals and disparages her strength and, by his admission, declared the latter died a pitiful death. All For One tarnished her memory by knowingly taking in and grooming her grandson, Tenko Shimura, to be a villain and his successor.