Mayumi Uchida, nicknamed Mayu-chan, operates as the starboard navigation controller aboard the Harekaze, responsible for monitoring and managing navigation from that position. This duty demands constant situational awareness and composure, especially during intense operations. She originates from Namegata in Ibaraki Prefecture. Born on December 6th, she is a Sagittarius, stands 158 cm tall, and has blood type B. Her physical traits include tan skin from sun exposure, distinctive purple eyes, and dark hair typically styled in a braid tied with a blue-green bow on her left side; her uniform features a longer skirt reaching knee level. Personality-wise, Mayumi consistently manifests a calm demeanor, particularly under high-stress situations like battle. This aligns with the Filipino/Tagalog meaning of her name, "tender, soft, modest," while her Japanese name combines "真" (real, genuine) and "弓" (archery bow). Academically, she favors political science and economics but finds physics challenging. In terms of food, she prefers tuna sushi and dislikes barley rice. Judo serves as both her hobby and special skill. She lives by the personal motto "Make a fortune at a single stroke," reflecting a focus on seizing decisive opportunities.