The story picks up with the protagonist, Ritsuto, in class, bored by a math lesson. His childhood friend, Kaiharu, sits beside him, fast asleep. Ritsuto, motivated by a desire to prevent Kaiharu from failing and facing the prospect of repeating the year, playfully tickles her side, waking her up and inadvertently causing her to be called on by the teacher. Kaiharu, flustered and confused, calls out Ritsuto, who feigns encouragement.
After school, Ritsuto and Kaiharu walk home, with Kaiharu still upset about the classroom incident and demanding ice cream as compensation for her embarrassment. Ritsuto, though claiming financial strain due to living alone, agrees to buy her ice cream, admitting he can't promise not to play such pranks again, much to Kaiharu's frustration. During their walk, Ritsuto reflects on how much his hometown has changed in the three years since he returned, a sentiment Kaiharu shares, acknowledging his return was based on a childhood promise.
As they approach the ice cream shop, Kaiharu excitedly pulls Ritsuto forward, but their arrival is met with the presence of another student, Arisu Reika, the student council president. Reika, a strikingly beautiful girl, is about to leave when Ritsuto calls out to her. Kaiharu, clearly disliking Reika, sarcastically points out that the student council president wouldn't be buying snacks. Reika then departs without a word.
Later, Ritsuto and Kaiharu discuss their strained relationship with Reika, with Kaiharu expressing strong animosity and warning Ritsuto not to get involved. Kaiharu then pointedly asks Ritsuto if he likes Reika, to which he honestly admits he does. This causes Kaiharu to become visibly upset and sad, stating that Reika has no interest in them.
The next day, an emergency school assembly is called. The principal announces that Arisu Reika was involved in a traffic accident the previous afternoon and is currently in a coma. Ritsuto is deeply shaken by this news.
He visits Reika in the hospital, finding it difficult to accept her condition. Later, back in his apartment, Ritsuto hears a noise and, suspecting a burglar, enters his room to find Arisu Reika standing there, looking confused and wearing white attire. He realizes it's her, despite her unusual appearance. Reika explains that after the accident, she found herself in his room, unsure of what happened. Ritsuto suggests she might be experiencing astral projection, or a "living spirit."
Reika agrees that this is the only explanation and expresses a desire to return to her body, but first asks Ritsuto to grant her one "wish": to hold her hand. Ritsuto complies, placing his hand where hers would be, unable to feel physical contact but acknowledging her presence. He recalls a childhood memory of comforting a crying Reika, whom he had defended from bullies. He remembers telling her he liked her hair color and asking her to play. This memory highlights their past friendship, which included Kaiharu, and the promise Ritsuto made to return.
Ritsuto wakes up alone in his apartment, with a blanket draped over him, realizing Reika must have left it before departing. He cherishes the memory of holding her hand.
Meanwhile, Reika awakens in the hospital. Her father visits, inquiring about her studies. She then checks her phone, finding no messages from her classmates or Ritsuto and Kaiharu, as she doesn't have their contact information. A teacher also visits, and Reika, acting mechanically, inquires about student council matters.
The next day at school, Ritsuto hears classmates discussing Reika's recovery. He feels a bittersweet emotion, reflecting on their brief, dreamlike encounter. Kaiharu notices his mood, and they engage in a playful argument about Ritsuto's perceived obliviousness.
Upon returning to his apartment, Ritsuto is greeted by Reika, who is now wearing an apron and tidying up, preparing dinner. She explains that she returned to her body once after her wish, implying she can do so again. Ritsuto, amused by her logic, accepts her offer to cook.
While shopping for ingredients at Reika's request, Ritsuto encounters Kaiharu, who is surprised to see him buying groceries and comments on his unhealthy eating habits. Ritsuto deflects Kaiharu's suspicions about who is cooking.
Back at his apartment, Reika expresses concern about Ritsuto's reliance on instant noodles. Ritsuto suggests that with her around, he won't have to worry, causing Reika to blush and become flustered. She eventually begins preparing dinner, humming cheerfully. Ritsuto reflects on the surreal nature of Reika's presence, considering her an "irregular" manifestation of his wish for warmer times with his friends.
Reika serves a delicious meal, which Ritsuto thoroughly enjoys, expressing his genuine appreciation. Reika, relieved, smiles innocently.
