Makoto Yūki is a member of the idol unit Trickstar at STARMARKER PRODUCTION. His background includes experience as a child model, where he developed strong posing techniques and situational awareness. This career led to significant emotional strain, resulting in a severe fear of cameras that caused him to freeze or react negatively when photographed during his early years at Yumenosaki Academy. Trauma from industry pressures that prioritized work obligations over personal feelings shaped his tendency to suppress emotions to fulfill professional demands. He enrolled at Yumenosaki to repurpose his modeling skills into idol work, seeking a less pressured environment. Despite ongoing insecurities about his idol abilities compared to his natural modeling talent, he remains committed to idolhood and refuses to return to modeling.

Personality-wise, he presents as easy-going and lively, often serving as Trickstar's social media manager due to his tech proficiency. He embraces the role of the "funny guy" in group dynamics, though he frequently functions as the "straight man" during comedic exchanges. His hobbies center on gaming, particularly fighting games, and he appreciates "kusoge" for their replay value. He is observant of others' emotional states, offering support to unit mates like Mao Isara during slumps. Additional traits include social awkwardness around girls and strong skills in electronics tinkering and online information gathering, which he uses to support Trickstar's activities. His gaming expertise surpasses other characters, with Animal Crossing as a confirmed played title.

Character development shows his gradual recovery from camera trauma through Trickstar's support. Intensive training bolstered his confidence, leading to self-acceptance. A pivotal moment occurred during a joint live with Knights, where he confronted former model colleague Izumi Sena about past demeaning treatment and asserted his identity as an idol. Later, during the New York Idol Film Festival trip, he utilized martial arts training from Yuzuru Fushimi to participate in defensive sports duels against antagonists. He displayed empathy for Macky—a lookalike manipulated to frame him—and expressed concern for Macky's welfare after the festival incident.

Physically, he has green eyes, short dark-blonde hair parted to the right, and wears blue-rimmed glasses. His stage attire features Trickstar's signature blue plaid jacket with gold accents, fingerless gloves, and a four-pointed star necklace symbolizing the unit. Casual wear includes layered outfits like a beige button-down over a tee with teal jeans in warm weather and a tri-colored jacket with a hoodie in colder seasons. Merchandise depictions consistently highlight his glasses and star-motif accessories. His autograph incorporates his name in kanji with a smiley face. His name etymology reflects "truth/genuineness" (Makoto) and "courage" (Yūki, homophonous with 勇気).