Tenji Mikasa is a top-ranked high school student renowned for his exceptional intellect. He maintains a serious demeanor yet possesses strong communication skills that earn him popularity with teachers and peers. His appearance features short, spiky dark hair, green eyes, and distinctive rectangular-framed glasses; he typically wears his school uniform. Following his father's death, Tenji faces significant financial hardship. Lacking family support, he relies on scholarships for his education while aspiring to study law at T University to become a lawyer. His father died shortly after disclosing information about the Tomodachi Game and attempting to meet Shiho Sawaragi's father. Tenji blamed Shiho for this tragedy, fueling a deep-seated obsession with exposing her. This fixation began in middle school, where he systematically destroyed Shiho's other relationships to make her solely reliant on him. His methods included deceit, such as framing Shibe's father to erode Shiho's trust, despite Shibe having previously assisted him. Tenji instigated the main events by stealing two million yen designated for his class's school trip. He used a bugged self-defense alarm he had given Shiho to monitor her and locate the money. He then enrolled himself and four others—Yuuichi Katagiri, Shiho Sawaragi, Makoto Shibe, and Yutori Kokorogi—into the Tomodachi Game to settle his debt and exact revenge on Shiho. Within the first two games, he served as the traitor. He manipulated group dynamics by spreading lies, like falsely claiming Yutori sold her body for money, to fracture Shiho's friendships. After initial exposure, he feigned a mental breakdown and shed crocodile tears to deflect suspicion. A pivotal shift occurred when Tenji discovered Shiho was not responsible for his father's death. This revelation prompted him to abandon antagonism and collaborate with Yuuichi. During the third game, he endured extreme dehydration and starvation while hiding, demonstrating unwavering faith in Yuuichi's strategy to prolong the game. His loyalty solidified when he defiantly rejected an opponent's offer to betray Yuuichi; this act directly led to his physical discovery but affirmed his commitment to their alliance. Post-redemption, Tenji evolved into a determined ally, aiding Yuuichi in dismantling the Tomodachi Game's administration. He exhibited tactical prowess, disguising himself among "zombie" players to evade detection and participating in complex gambits to destabilize rival groups. Adjusting his glasses when strategizing became a noted behavioral trait. Personality assessments categorize him as an ISTP with Enneagram Type 8w9 traits, highlighting his analytical approach, desire for control, and strategic manipulation.