After giving up on making friends in elementary school, Chie Suzuki has settled into a comfortable solitude, presenting herself as a cool, aloof beauty content to live in her own world at school. Her only real irritation is the character overlap between herself and Satou, the handsome, top-ranking student known as the Ice Prince for his expressionless demeanor. She finds him frankly annoying, until the day Satou surprises her by asking, Will you be my friend? Chie initially refuses, having long convinced herself that making friends requires some kind of special skill she lacks. But Satou persists, revealing that behind his icy reputation he is simply a pure-hearted boy who has never been able to connect with others. He proposes a compromise: since neither of them understands how friendship works, why not try being temporary friends? Chie reluctantly agrees, and together they begin an unconventional experiment in human connection.

The series follows Chie and Satou as they navigate their tentative arrangement, using a sugoroku-style stamp card to track their progress through friendship milestones. Their early attempts are awkward and self-conscious: exchanging mysterious letters during lunch, attempting a game of catch under the open sky, and investigating rumors of a ghost in the old school building. Each small step forces both of them to confront emotions and experiences they have long avoided. Satou struggles to express himself openly, while Chie grapples with the vulnerability that comes with letting someone into her isolated world. Their growing bond draws the attention of their classmates, including Tagata, a keen observer who quickly becomes a supportive ally even as he nurses his own unspoken feelings toward Satou.

As the story progresses, the pair face more complex challenges that test their fragile friendship. A double date with a group of gyaru girls forces them to navigate social situations neither is prepared for. The approach of the cultural festival creates new pressures: buried in preparation duties, Chie and Satou struggle to find time for their temporary friend activities, and a rift begins to form between them. Chie finds herself puzzling over unfamiliar sensations she cannot name, while Satou grows increasingly unsure of how to bridge the distance. Meanwhile, Tagata wrestles with his growing affection for Satou, adding another layer of emotional tension to the group dynamic.

In the latter part of the story, having weathered various doubts and misunderstandings, Chie and Satou deepen their trust and settle into a more comfortable rhythm. They visit Chie's home, celebrate birthdays together, and share simple daily pleasures with the friends who have gathered around them. However, a major incident arises that threatens to unravel everything they have built, forcing both to reckon with what their relationship truly means. The series concludes as Chie and Satou, along with their circle of companions, navigate this final crisis and discover whether their temporary friendship can become something real and lasting.