"Kanzeon" (観世音) is the Japanese name given to the Chinese goddess of mercy and compassion, Guan Yin. According to the teachings of Buddhism, she originated from the Bodhisattva Avalokiteśvara, a male figure, before becoming a deity. Her being is mostly depicted as a beautiful woman wearing a white robe and carrying a jar of pure water and a willow branch. In her meditations, she attempted to aid the ones who needed her, but with only two hands at her possession, she was unable to do it until Amitabha Budha, her spiritual teacher, gave her a thousand arms so that she could complete her task. Guan Yin is so popular in East Asia regions that she received different names. Her origin and history in each region also differs from one another.
While not seen directly, Kanzeon is referenced during the third Vision Quest, in the form of Naomi's special "Kanzeon Redemption" skill, which temporarily boosts her max HP. This is the only spell exclusive to Naomi that Nemissa cannot learn later on in the game. However, this effect can occur via items instead.
Following the event of maxing the Social Link of the Lovers Arcana, Rise Kujikawa comes to realize her true desire to become an idol once again but now with the goal of showing her true self. This is when Himiko evolves into her Ultimate Persona Kanzeon. Kanzeon will inherit all status and abilities of Himiko and can automatically detect enemies' weaknesses right at the start of any battle, using Weakness Scan. Her concept design also changes, showing her skin to be silver colored instead of black, her satellite on her head being modified and even gains two at each of her hips. The device she carries also switches color from gold to red and her robe also transforms into a more revealing one with vertical patterns of white and black. Kanzeon has retained most of the abilities of Juno, her counterpart in Persona 3, with the notable exception of Oracle and Escape Route, however, she gains new abilities in their place.