Kō Sakuragi possesses short brown hair with face-obscuring bangs, dark green eyes, thick black eyebrows, full-framed glasses, and a beauty mark below her left eye. Her standard outfit combines a cream sweater over a light blue blouse, gray slacks, sneakers, and white headphones resting around her neck. At 170 cm tall, her appearance consistently causes others to misidentify her as male—a misconception she never disputes due to profound shyness. Social anxiety defines Kō's behavior, manifesting as incessant apologies, evasive eye contact, and deliberate avoidance of interactions. Friendless and disconnected from social media, she initially finds verbal expression nearly impossible. Despite this isolation, she craves connection and immerses herself in video games, often losing awareness of her environment during play. This passion stems from childhood gaming sessions with her supportive father. She first meets Naoya Nifuji at Startbox café while gaming. Naoya, recognizing her reserved demeanor mirrors his brother Hirotaka's, approaches her about the game, startling her into fleeing and leaving behind a document. He later returns it at their university and proposes friendship, which she misinterprets as a gaming friend request, sparking their online bond. Naoya, still believing her male, notes her kinder gaming style compared to Hirotaka and her preference for multiplayer games. Their friendship evolves through arcade visits and meetings with Naoya's friends—Yokkun and Ken, Kou's former high school classmates. Tension erupts when Naoya accidentally discovers her gender after she exits a women's restroom, prompting her to avoid him fearing rejection. Guided by Narumi Momose and Hirotaka, Naoya locates her in-game via Hirotaka's account, apologizing during a cooperative monster battle. This reconciliation deepens their friendship, increasing Kou's comfort in social outings. Kou develops unspoken romantic feelings for Naoya but deems herself unworthy due to her introversion versus his extroversion. She withdraws by taking a part-time job, using work to decline hangouts. When Naoya finds her crying and consoles her, he confesses his feelings, easing her doubts, and she accepts dating him. Their relationship advances, earning Hirotaka's gratitude for Kou's positive impact on Naoya's growth. Later, Kou formally meets Narumi and Hirotaka during an arcade trip, where Hirotaka commends her gaming skills. She bonds with Narumi over manga, though anxiety initially makes her forget Narumi's name and face. In a notable moment, Kou flees when Naoya offers to share an umbrella in the rain—a culturally significant gesture—but he catches up, and they walk together. The manga's afterward hints at a future proposal where Naoya plans to defeat her in-game to propose, though she remains unaware and keeps winning. An illustration shows Kou with longer hair, new glasses, and a smile, affectionately calling Naoya "Nao-chan," signaling their closeness. Kō interacts cautiously with others: admiring Narumi's brightness while fearing Hanako Koyanagi's exuberance and Tarō Kabakura's intensity. Kabakura mistakes her for a male shojo manga fan and attempts friendship, but she retreats from his approach.