Nikki Hanada, also known as Niki Hanada, hailed from modern-day Japan before the petrification event. Childhood bullying over her butch appearance drove her to find solace in pop idol Lillian Weinberg's music, transforming her into a dedicated superfan with encyclopedic knowledge of Lillian's career stats, CD sales, and physical details. Her school life revolved around the judo club, where rigorous training leveraged her large build and strength, earning her the "boss" nickname from underclassmen. This daily exertion often left her visibly bruised, with bandaged hands apparent just before petrification. Physically distinctive, Nikki possesses an athletic build and stands 1.80 meters tall. Her blonde hair and imposing stature ensure a noticeable presence. Her personality blends fierce loyalty, protective instincts, and physical courage. She exhibits unwavering dedication, particularly to Lillian Weinberg's legacy. While her tough judo-honed exterior is prominent, underlying affection and emotional vulnerability remain. Nikki communicates straightforwardly but shows flustered reactions, like when confronting Gen's deceptive romantic ploy involving Hyoga. She possesses practical English skills, facilitating interactions with the American Colony. Initially revived into the Tsukasa Empire, Nikki performed surveillance duties under Tsukasa's command. She monitored Taiju Oki and Yuzuriha Ogawa near Senku Ishigami's fake gravesite, mistaking Taiju's shouts for grief rather than covert signals. Her pivotal defection to the Kingdom of Science occurred when Taiju and Yuzuriha brought her to the gravesite. Hearing Gen Asagiri's imperfect Lillian impression, she tested their authenticity with Lillian trivia. Senku ultimately convinced her to switch sides by playing an actual Lillian voice recording and promising to preserve the last surviving copy. Nikki's realization of Lillian's death cemented her resolve to protect the recording. Post-defection, she helped Gen refine his impersonation. As a Power Team member in the Kingdom of Science, Nikki contributed to critical operations. She assisted excavating petrified individuals, including Ryusui Nanami despite initial reservations about his character. Her strength proved vital during road construction and retrieving petrification devices. During the Treasure Island conflict, Kirisame ordered her petrification; she was later successfully depetrified. In subsequent battles, she demonstrated tactical awareness by preventing misguided attempts to activate petrification weapons at incorrect distances. Nikki joined the voyage to America aboard the Perseus. She witnessed Tsukasa Shishio's revival upon returning to Japan and observed interpersonal dynamics between Minami and Ruri. Confronted by Stanley Snyder's American forces, a female soldier subdued her; she was later detained with other crew members. Her English proficiency facilitated negotiations with Dr. Brody, where her assertive intervention helped secure agreements favorable to the Kingdom of Science. In the South America arc, Nikki contributed to diamond synthesis and witnessed Joel Gear's revival for authentication. She actively engaged in combat against American soldiers during the mission to secure the petrification weapon. Shot in the torso, she maintained resolve by emphasizing survival as long as breathing continued. Joel Gear's activation of the Why-man's signal ultimately petrified her again. After a nine-year interval, Taiju's group revived her alongside others upon returning to America.