Amaryllis, regarded as the most beautiful resident of Treasure Island, received multiple marriage proposals daily before meeting Senku's group. At age twelve, she and four friends broke island rules by sailing offshore. As punishment, the Master's warrior Kirisame deployed a grenade-like device emitting green light that petrified her companions. Amaryllis narrowly escaped full petrification by tearing off her hair where the light grazed her, cementing her belief that petrification functioned as a weapon. This event forged her long-term strategy: she cultivated her beauty deliberately to gain entry into the Master's inner palace, intending to locate and steal the petrification device to liberate the island. Encountering Senku, Chrome, Kohaku, Gen, and Soyuz during their reconnaissance, she sought their help. She recounted her backstory and objective precisely for strategic planning. Collaborating with the Kingdom of Science, she aided the infiltration of the Master's selection for the inner palace. Her expertise in cosmetics proved vital for disguising Kohaku, leveraging years of preparation. She suggested including multiple candidates to increase their odds, resulting in Ginro's reluctant crossdressing participation. Minister Ibara selected all three. During the mission, she maintained composure when Ibara attempted to assault Kohaku, an incident halted by Mozu's intervention. She later witnessed Ibara petrifying Kohaku and Ginro, memorizing details while visibly distressed. She reported this critical intelligence to Senku for countermeasures.