Niki Hanada is a modern-day survivor revived by Tsukasa Shishiou who later defects from the Tsukasa Empire to join the Kingdom of Science. Her primary motivation for switching sides is to protect the last surviving copy of a song by Lillian Weinberg, a singer whose music had a profound impact on her life. In the modern world, Niki faced a difficult time at school, and Lillian's songs gave her emotional support, making her a devoted fan. She has a tall, athletic, and muscular build, the result of her background as a judo athlete; during her school years she trained daily, often leaving her bruised and cut, and her underclassmen called her "boss." She has blonde hair braided into two ponytails tied with blue bows, expressive green eyes, and a blood type of AB. Her birthday is July 4. Within the Kingdom of Science, Niki is a member of the Power Team and unofficially serves as a disciplinary figure, frequently keeping others in line. She is known for her physical strength and stamina. During the New World arc, she becomes a crucial laborer in the construction of Corn City on the North American continent, contributing to the kingdom's large-scale settlement projects. Her key relationships include her admiration for Lillian Weinberg, her loyalty to Senku Ishigami and the Kingdom of Science after defecting, and her camaraderie with other former Tsukasa Empire members. Over the course of the story, she develops from a soldier serving under Tsukasa into a committed and hardworking member of the scientific community, using her strength and dedication to support the kingdom's goals.