Nana Yamamoto is a character from the anime Bokura ga Ita, serving as the older sister of Yuri Yamamoto and the first girlfriend of the male protagonist, Motoharu Yano. She died in a car accident alongside her ex-boyfriend approximately one year before the main events of the story take place. Her sudden death leaves a deep emotional scar on Yano, shaping much of his cautious and distrustful behavior throughout the series. Personality-wise, Nana is described as being the opposite of her sister Yuri, and her temperament is noted to be similar to that of the female lead, Nanami Takahashi, who is often called Nana-chan. Because of the shared name, those around her refer to her as Nana-san to avoid confusion. She remains a significant off-screen presence whose memory influences Yano’s romantic difficulties and his inability to fully open up to Nanami. While she does not appear in the present-day narrative as a living character, flashbacks and conversations reveal her role as Yano’s first love, and the circumstances of her death—occurring while she was with an ex-boyfriend—fuel Yano’s lingering doubts about trust and fidelity. Her legacy is ultimately addressed when it is later revealed that she had not been unfaithful, but had simply gone to properly end that past relationship. Nana’s character serves as a catalyst for much of the emotional conflict and growth experienced by the main characters, particularly Yano and Nanami. No notable abilities or further character development are depicted, as she exists primarily as a memory and a plot device.