Mayumi Fujiyama is a character from the anime Office Lingerie, also known under the title Lingeries. She works in the Planning Department, specifically within Planning Division 2, as a direct subordinate to the protagonist, Yusuke Nakanishi. In some descriptions she is referred to as his secretary. She has a calm and composed personality, but she is also noted for her lively manner and tendency to talk rapidly, often making minor mistakes in her work. Despite these small errors, her creativity and planning skills are described as outstanding. However, her motivation has been waning due to the corrupt and demoralizing atmosphere that has taken hold in Planning Division 2.

Her role in the story is to assist the protagonist in his mission to root out corruption within the lingerie company Best Beauty Body Inc. Unlike some of her colleagues who have become cynical or complacent, Mayumi still retains a degree of passion and idealism. She provides support and information, helping Yusuke identify and approach other capable female office workers in order to gather intelligence through manipulative means. As the protagonist begins to show results, the morale and behavior of the people in Planning Division 2 gradually start to improve.

Mayumi develops romantic feelings for her boss early in the story. Among the main female characters, she is notably the only virgin. Physically, she has short brown hair and yellow eyes. Her character does not undergo a dramatic transformation over the course of the series, but she does play a key part in the gradual cultural shift within her department, moving from a state of disillusionment toward renewed engagement. Her abilities lie primarily in strategic thinking and organizational planning, which she uses both in her official duties and in helping Yusuke carry out his plans.