Erika Kiriya is a main character from the visual novel and anime Tsuyokiss, known as the student council president at the school she attends, where she is a second-year student in class 2-C. She is the daughter of a powerful and wealthy family that runs the large Kiriya Corporation, and she is of mixed American and Japanese heritage. Her birthday is on December 31st, and she stands at 165cm tall with blonde hair and blue eyes.

Nicknamed Hime, meaning Princess, by her peers, this title is given with both respect and irony due to her haughty and nearly perfect nature. Erika is an ambitious, confident, and charismatic individual who is also openly arrogant, sharp-tongued, and self-centered. She is an exceptional student, consistently ranking at the top nationally, and possesses outstanding athletic abilities, to the point where she can easily overpower most of her male peers. She exudes a commanding presence and expects others to follow her orders, preferring to be called King rather than Princess, as she feels it is a higher designation. Despite her domineering exterior, she has several quirky personal interests, including being a fan of Boys Love literature, for which she uses her real-life acquaintances as inspiration, and she enjoys collecting attractive underclassmen of both genders. She is also known for a strange, unique ability to make roses bloom spectacularly in the background when she strikes a pose, a trait that annoys her grandmother who has to clean up the petals.

A primary motivation for Erika is her ambition to rise to the top of her family's corporation and ultimately expand her influence to control the global market, driven by a desire to test the limits of her own abilities. This ambition is tempered by a deep-seated sense of loneliness and distrust of others; due to her immense wealth, she is constantly aware that people might betray or deceive her for their own gain. As a result, she is guarded, never sleeping in the presence of others, and actively seeks people she can genuinely trust to be by her side as she climbs to the top.

In the story, Erika acts as a primary obstacle for protagonist Sunao Konoe, who wishes to start a drama club, as the student council under Erika's rule initially opposes the idea. She has a close and trusted friendship with Yoshimi Satou, who is noted as the only person Erika sincerely trusts without reservation. She also holds deep respect for senior student Otome Kurogane, who is one of the few people capable of curbing Erika's worst impulses. Her relationship with the male lead, Leo Tsushima, is central to her development. Initially viewing him as an unremarkable and timid boy, she becomes interested in him after witnessing his hidden resolve and integrity. She begins dating him, but their relationship is initially framed as an experiment or a contract, with Erika making demands and testing his patience. Over time, however, she begins to develop genuine affection for him, which forces her to confront complex emotions like jealousy and consider the balance between her personal ambition and her relationships.

Erika's character development sees her transform from a purely self-interested, untouchable figure who treats people as tools or entertainment into someone capable of forming genuine emotional bonds and acknowledging her own vulnerabilities. She learns to navigate friendship and romance, realizing that her singular focus on the future does not have to come at the complete expense of personal connections. Her notable abilities include her superhuman academic and athletic prowess, a fearsome skill in martial arts, and a natural talent for leadership and command. Despite her many strengths, she has a notorious lack of artistic and aesthetic sense, often producing or admiring things that others find eccentric or garish.