Tanuki, a high school student at a prestigious school, lives with his older stepsister Komaru, a 21-year-old who attends a correspondence school located right next door. Despite sharing a home, their relationship is strained: Komaru is constantly rude, abusive, and dismissive toward Tanuki, and her problematic behavior at school has earned her a reputation that reflects badly on both of them. The students at Tanuki’s school openly mock the correspondence school students, adding social pressure to the tense household. Tanuki, however, wants to restore a sense of family and decides he has had enough of her attitude. Encouraged by a friend who suggests that Komaru’s abrasive exterior might hide a softer, cuter side, Tanuki devises a plan to “handle” her—essentially, to break through her pride and make her show her true feelings. His approach involves a mix of persistence, kindness, and sometimes confrontational tactics, all aimed at helping her shed her defensive shell. As the story unfolds, Tanuki’s efforts gradually chip away at Komaru’s hostility. She begins to reveal moments of vulnerability and clumsiness, hinting at the insecure and lonely person beneath the gyaru persona. The narrative progresses through several arcs: early chapters focus on establishing their strained dynamic and the first attempts at reconciliation, including a memorable incident involving sushi that sparks rumors at school. Later, a passionate teacher named Higashioka enters the picture, attempting to guide Komaru toward a better future, while Tanuki’s own “excessive” methods become a point of contention. A significant turning point comes with the introduction of Mochizuki, a girl from Tanuki’s class who develops feelings for him. Her presence complicates the sibling relationship, as Komaru begins to feel jealous and possessive, forcing her to confront her own emotions. The sports festival arc sees Tanuki orchestrating a special strategy to help Komaru gain confidence, while Mochizuki’s manipulations push Komaru into a noticeable transformation. The story explores themes of family, self-worth, and the messy process of opening up to others, all set against a backdrop of everyday school life and the gradual softening of a once-brash older sister.