Niki Hanada, known as Nikki, grew up in the pre-petrification era enduring childhood bullying. She found solace in Lillian Weinberg's music, evolving into a devoted fan with encyclopedic knowledge of Lillian's career specifics—CD sales figures, physical measurements, and concert attendance. Nikki joined her school’s judo club, capitalizing on her robust physique through intense training; underclassmen dubbed her "boss," and fresh bruises and plasters on her hands marked recent practice sessions just before the 2019 global petrification. Revived under the Tsukasa Empire, Nikki monitored Taiju Oki and Yuzuriha Ogawa near Senku Ishigami’s decoy grave. Taiju’s persistent appeals drew her to the site, where Gen Asagiri’s imitation of Lillian prompted her to quiz the group. After their incorrect answers, Senku played an authentic Lillian recording. Recognizing the singer’s voice and learning of her death, Nikki defected to Senku’s Kingdom of Science in exchange for his vow to safeguard Lillian’s last record. She later refined Gen’s vocal mimicry. As a Power Team member in the Kingdom of Science, Nikki contributed to road-building and excavation. She aided in reviving sailor Ryusui Nanami despite Minami’s cautionary description. Frequently serving as enforcer, she restrained volatile allies like Magma and Yo. Her strength—rated 4 out of 5—allowed her to confront adversaries such as Oarashi during the Treasure Island Arc to thwart petrification-device misuse. Petrified twice on Treasure Island, she was later restored. Nikki revealed unexpected traits: favoring vibrant fabrics during balloon construction, displaying notably girlish handwriting on photo captions, and expressing interest in modern clothing once Yuzuriha mass-produced garments. Gen Asagiri observed her feminine nature when she flustered at his suggestion to feign affection for Hyoga. During the America voyage, she employed self-taught English—acquired to comprehend Lillian’s lyrics—to negotiate with Dr. Brody for Corn City. In the South America Arc, Nikki helped synthesize diamonds to authenticate Joel Gear’s watchmaking. Joining the fight for the petrification device, she suffered a torso gunshot from Brody’s soldiers. Bleeding but conscious, she stressed survival hinged on continued breathing. She succumbed to her injury and was petrified after the device activated. Revived roughly nine years later, she witnessed updates concerning the Why-man entity.