Rika Tokino actively operates the Tokino Bath House alongside her older brother Kazuto. Pragmatic and financially driven, she persistently worries about the bathhouse's economic viability, viewing it as a potential liability. This monetary focus once led her to nearly sell Valkyrie for a lucrative offer, though the deal failed due to counterfeit currency.

She consistently serves as the straight man (tsukkomi) in comedic scenarios, reacting rationally to absurd or supernatural events involving the bathhouse and its alien visitors. Academically ambitious, Rika prioritizes studies to gain entry into a reputable high school and university. This dedication prompted her to reject romantic advances from her school's most popular boy, resulting in a later platonic friendship.

Her relationships with Valhallans are complex: while occasionally annoyed by Valkyrie's antics, she considers her a friend. Interactions with princesses like Laine and Chorus mix irritation at their disruptive behavior with underlying concern. She addresses Princess Mehm as "auntie" (contrary to Mehm's preference for "big sister"), reflecting her pragmatic view of Valkyrie and Kazuto's marriage as a financial opportunity. Rika discusses personal insecurities, such as Akina Nanamura's feelings about her breast size, within their friendship.

Protective yet critical of Kazuto, she admires his dedication to preserving their grandfather's bathhouse but wishes he were more perceptive. She actively supports his romantic relationship with Valkyrie, primarily motivated by the financial stability their union could bring. Rika assigns nicknames, including calling the child-form Valkyrie "Valkyu."

Her role remains consistent across all documented media, maintaining her position as a supporting character who balances comedic elements with grounded concerns about family finances and academic responsibilities.