Azusa B. McLaren is a journeyman-level Single Undine affiliated with Himeya Company, directly mentored by Aika S. Granzchesta. Her personality combines bravery, directness, and self-confidence, often driving her to act impulsively without prior thought when something captures her interest. She relies on an electronic organizer to systematically record important information.

She shares a close friendship with Anya from Orange Planet Company, regularly practicing gondola skills together. This bond leads Azusa to collaborate with Anya and Ai in "Aria the Crepuscolo," working to facilitate a meeting between their seniors Alice and Athena. The seniors face conflicting schedules, and Anya observes Alice appears to be avoiding Athena.