Ririka Moriya is a bubbly, clumsy 4th grader who has a crush on Nozomu Kano, a transfer student from England. On her 10th birthday, Nozomu gives her a magical nurse cap, which allows Ririka to transform into the heavenly guardian, Nurse Angel. Nozomu later tells her that his real name is Kanon, and he comes from the planet Queen Earth, which has been overrun by the evil Dark Joker Organization, who has tarnished Nozomu's world through mass pollution. He was sent to find the legendary Nurse Angel, who would save both Earth and Queen Earth from destruction by finding the Flower of Life (命の花 Inochi no Hana). With help from Nozomu and her friend and neighbor Seiya Uzaki, Ririka learns to fight as Nurse Angel to protect her friends.