The protagonist, Hayakawa Seiya, a mob character reincarnated into a dating simulation game, finds his predetermined role disrupted. His mission was to confess to a heroine, be rejected, and then disappear from the story. However, a mistake leads him to confess to Hinamori Saki, a "Saint" heroine, instead of the intended Shinohara Reina, the "Goddess" heroine. Saki, though surprised, rejects him, fulfilling the rejection part of his role, but the unexpected interaction causes a ripple effect.
The next day, Seiya notices the school buzzing about his confession to Saki. Saki, visibly distressed by the rumors, approaches Seiya to discuss the situation. Seiya reassures her that she is not at fault and apologizes for the trouble he caused. Their conversation is interrupted by the school bell, but Saki quietly remarks on Seiya's kindness. Meanwhile, Shinohara Reina observes the gossip with a cold gaze.
During a break, a male student, Tanaka, confronts Seiya, mocking him for confessing to Saki. Just as Tanaka's insults escalate, Reina intervenes, silencing him with her sharp words and logic, pointing out his own hypocrisy. She then addresses the rest of the class, admonishing them for mocking Seiya. Saki returns, unaware of the confrontation, and Seiya thanks Reina for her help, though she dismisses it as an act to restore her reading peace.
Later, Seiya visits an arcade for a change of pace and encounters Reina. She is trying to win a plush toy for her younger sister, Yuina, but has run out of money. Seiya, feeling indebted to her for intervening earlier, offers to win the toy for her. He succeeds on his first try, impressing Reina. He also learns about Reina's deep affection for her sister, Yuina, and her "sis-con" tendencies. Reina, touched by his gesture, thanks him and promises to see him tomorrow, a statement that surprises Seiya.
The following day, Reina asks Seiya to meet her during the next break. They go to the rooftop, where Reina expresses her gratitude for the plush toy and shares a photo of Yuina happily holding it. During their conversation, Seiya inadvertently compliments both sisters, causing Reina to blush and playfully accuse him of being a "womanizer." Their conversation is cut short by the bell.
During art class, students are paired for a drawing assignment. While the boys swarm Hinamori Saki, Seiya is unexpectedly paired with her. Saki explains she chose him because she feels more comfortable with him than strangers and believes he won't mock her poor drawing skills. They go to a secluded spot in the school's backyard to work. Their drawing session is interrupted by the arrival of the protagonist, Tachibana Yuto, and an unknown female student, Fujimiya Shizuku, who are also working on their assignment. Seiya recognizes Fujimiya as a mob character who is rumored to be a hidden heroine. He observes Tachibana and Fujimiya's budding relationship, which seems to be progressing rapidly. Seiya is then pulled back to his task by Saki, who is embarrassed by his gaze.
Later, as Seiya and Saki are leaving school, Reina invites Seiya to her house. She explains that Yuina wants to thank him directly for the plush toy. At Reina's house, Seiya meets Yuina, who is delighted to see him and calls him "Kuma Onii-chan" (Bear Big Brother). He also meets Reina's mother, Sana. Yuina leads Seiya to Reina's room, where they are joined by Reina. Seiya learns that Yuina knew Reina didn't win the toy herself because she's bad at games, but still loves her sister. Yuina then declares she loves Seiya too, causing Reina to become jealous.
The next day, Seiya accompanies Reina and Yuina to a shopping mall. Yuina insists Seiya join them, and Reina, after initial hesitation, agrees. They have lunch, and Seiya compliments both sisters. Yuina asks Seiya to feed her, which he does, leading to a playful moment. Later, while Reina is in the restroom, Yuina asks Seiya to hold hands, inspired by a couple she sees. Seiya looks and realizes the couple is Tachibana and Fujimiya, who appear to be dating, a development that shocks Seiya as it deviates significantly from the game's original story. Yuina then reveals that she asked Seiya to hold hands because she wanted him to get a cat plush toy for Reina, as Reina had wanted it but couldn't afford it. Seiya retrieves the toy, and Reina, deeply moved, accepts it, calling Seiya a friend.
As Seiya walks home, he contemplates the unexpected turns of events, including the potential relationships between the heroines and the protagonist, and the emergence of other heroines. He resolves to speak with Tachibana the following week, unaware of an impending conflict.
