The protagonist awakens in a classroom, realizing they have been reincarnated into the world of a dating simulation game they were playing, "My Girlfriend Next Door is Just Too Sweet" (KanoAma). They are now Amatsuki Suzuna, an original character and one of the heroines, who is the childhood friend of the game's protagonist, Shindo Minato. Suzuna, the player, finds Minato's overbearing and condescending attitude towards her as the original Suzuna to be difficult to accept, and she resolves to avoid being romantically involved with him, aiming for a quiet, unremarkable school life.
As Suzuna walks home, she encounters another heroine, Hinase Riri, being harassed by a suspicious man. Remembering this event from the game, Suzuna realizes that Minato, who should have intervened, is absent due to her own decision to walk home alone. Overcome with guilt, Suzuna steps in, rescues Riri, and they leave together. Riri, a popular and outgoing girl, is grateful and expresses interest in Suzuna, despite their vastly different social standings. Suzuna, still trying to distance herself from the game's plot, is hesitant to form a close bond with Riri, fearing it will lead to further complications.
The next morning, Suzuna actively tries to avoid Minato, who expects their usual routine. She rejects his attempts at familiar physical contact and his use of the familiar nickname "Minato-kun," insisting on calling him "Shindo-kun" to create distance. Riri then appears, cheerfully inviting Suzuna to walk to school with her, much to Minato's confusion and Riri's apparent delight. Riri reveals she waited for Suzuna after their encounter the previous day, and their interaction leads to Riri believing Suzuna is interested in her, despite Suzuna's attempts to deny it.
During lunch, Minato is suffering from his sister Kokona's poorly cooked bento. Suzuna, having decided not to fulfill the original Suzuna's role of making his lunch, refuses to help, pushing him towards Kokona's route. Riri, having forgotten her own lunch, invites Suzuna to go buy food together. They end up at a cafe, where Riri, despite Suzuna's initial resistance and attempts to maintain distance, insists they are friends and shares her personal preferences and insecurities about her appearance and eating habits. Suzuna, though uncomfortable with the growing closeness and the attention it draws, finds herself somewhat drawn to Riri's genuine nature.
Later, Riri invites Suzuna to share a large pancake, which Suzuna reluctantly accepts. During their meal, Riri probes Suzuna about her preferences and past, inadvertently revealing Suzuna's knowledge of Riri's cooking habits, which Suzuna had learned from playing the game. This leads Riri to believe Suzuna is more interested in her than she lets on.
The following morning, Suzuna wakes up to a message from Riri, confirming their growing connection. She also finds herself walking to school with Kokona, who is upset that Suzuna has stopped fulfilling her role as Minato's childhood friend and lunch provider, believing Suzuna is giving up on Minato. Suzuna tries to explain she's simply acknowledging her own limitations and that Kokona is better suited for Minato, but Kokona is angered by Suzuna's perceived nonchalance. Riri then arrives, embracing Suzuna and further confusing Kokona, who is already suspicious of their interactions. Riri's cheerful demeanor and physical affection towards Suzuna, coupled with Kokona's growing frustration, create a chaotic start to the day.
