Zenji Marui is a first-year student at Totsuki Culinary Academy residing in Polar Star Dormitory. He possesses short black hair, black eyes, and requires glasses due to poor eyesight. His notably low physical stamina often leaves him appearing exhausted or decrepit after strenuous activities, sometimes necessitating a cane for support. This limitation causes some classmates to underestimate him, as he lacks the natural cooking talent of peers like Soma Yukihira. To compensate, Zenji focuses intensely on academic studies and culinary research, leveraging his sharp intellect and memory to remain competitive. This academic prowess earned him recognition as the ace of the Miyazato Seminar, dedicated to studying classical cookery philosophy and literature. Specializing in pastry, Zenji frequently carries sweets. His room in Polar Star Dormitory is the largest, making it a gathering spot for other residents despite his initial preference for solitary study. He reluctantly participates in their activities but cares deeply for them, forming a particularly close bond with Shun Ibusaki. His loyalty to the dorm community is evident during events like the Totsuki Friendship and Rapport Training Camp, where he perseveres through grueling assignments despite his physical limitations, collapsing from relief upon completion. During the Autumn Elections preliminaries in Block A, Zenji presented a White Potage Curry Udon dish. Judges noted its tranquil, smooth quality derived from a vichyssoise-style roux, contrasting with more aggressive entries. The dish earned 88 points, initially placing him second and later fifth after tiebreakers, eliminating him from the main tournament. He shared this placement with Shun Ibusaki, and both reacted by skipping celebratory events. In later arcs, Zenji attends the Autumn Election main tournament as a spectator, explaining technical aspects of opponents' cooking techniques to Polar Star residents. He participates in the rebellion against Azami Nakiri's administration. His academic focus and support for allies remain consistent traits throughout his appearances.