A former member of the JASDF, and currently the maid for the Takanashi household.
Prior to the events of the series, Kamoi had a chance encounter with Misha playing in the snow with her mother and was instantly smitten with her. Two years down the road, Kamoi has left the JASDF and is looking for a job. She sees the flyer put outside the Takanashi household, and immediately climbs a lamp post to see if it is the same Russian girl (much to Misha's shock and terror). Following their first proper encounter, Kamoi is hired as the Takanashi's new maid, much to Misha's chagrin.
Tsubame Kamoi is competent at her new job, able to cook, clean, and handle Misha's frequent antics to get her to leave.