Tsukasa Suou is the only child and heir of the Suou family, an old military lineage whose nobility stems from long history rather than contemporary wealth, earning them the label "poor nobles." This status drives his determination to expand the family's income sources to keep pace with other elite families. His frequently occupied parents enforced a strict upbringing, though his father valued independence and permitted his enrollment at Yumenosaki Academy. Following his father's illness, Tsukasa temporarily assumed the role of family head while balancing his duties as an idol. Raised with chivalric ideals, Tsukasa displays composure beyond his years, yet reveals childishness and a short temper in trivial disputes, especially with childhood acquaintance Tori Himemiya. Their rivalry began over contrasting paths to adult approval—Tsukasa diligently met expectations while Tori pursued personal interests like idol work. Tori's pity for Tsukasa's rigidity spurred self-reflection, ultimately leading both to idol careers. Tsukasa remains easily flustered by seniors' teasing and resists being treated as a child. Beneath a confident exterior lies deep self-doubt, often prompting him to seek guidance from Leo Tsukinaga, his predecessor in Knights. A significant childhood incident saw him become lost in the city, where a retired idol's lament about betrayal inspired him to pursue control over his future. Physically, Tsukasa possesses brownish-red mid-length hair, lavender eyes, and a fair complexion. He stands approximately 167-168 cm tall with an average build. His school uniform comprises a buttoned blazer, white shirt, tie, plaid pants, and dress shoes. Knights performances feature him in elaborate military-inspired attire: a dark blue-and-white tailcoat with gold accents, epaulettes, a cape, and black gloves, reflecting the unit's royal knight motif. As leader of the idol unit Knights under NEW DIMENSION, Tsukasa aims to earn recognition as the "King of Knights." He guides the unit with a focus on escorting their audience, the "princess," through dreamlike stages. Though a natural leader, he contends with the unit's individualism and his seniors' eccentricities, striving to balance authority with flexibility. His performances showcase an honest, dignified singing voice and elegant yet powerful staging. Tsukasa is bilingual, frequently incorporating English into his speech before self-correcting for clarity. He exhibits curiosity about commoner culture and enjoys sweets—initially as stress relief—alongside old books, chess, card games, and mobile games. He dislikes insects. Horseback riding is a specialized skill. His hobbies include writing web novels under the pen name SukaCheri, unknowingly admired by his distant cousin, Kohaku Oukawa. The Oukawa family, a branch of the Suous, historically handled "dirty work" for the main family. Tsukasa once protected Kohaku from a dog despite his own fear and later financially supported Kohaku's unit. Their relationship mixes familial loyalty with mutual snark, often centered on sharing sweet treats. Key relationships include his reverence for Anzu, whom he calls "Onee-sama" and serves as his "Queen." He exhibits jealousy toward rivals like Trickstar, particularly Subaru Akehoshi and Hajime Shino, for their closeness to Anzu or Eichi Tenshouin. He respects Eichi ("Eichi onii-sama"), though his enthusiasm often meets indifference. As roommates with Shinobu Sengoku and Souma Kanzaki at Ensemble Square, he bonds with Souma over mutual support and language study and admires Shinobu's dedication to origami. Tsukasa's pivotal development involved assuming Knights' leadership after Leo's departure during the Repayment Festival, coinciding with his temporary role as family head. This dual responsibility marked his growth from a self-questioning heir into a figure embodying both familial and unit stewardship.