Kono Aozora ni Yakusoku wo: Youkoso Tsugumi Ryou e

Wataru Hoshino's life takes an unexpected turn when he discovers a girl, Rinna Sawaki, asleep in his room, clad only in her underwear. After a startled awakening, Rinna escapes through the window, leaving a bewildered Wataru—and a punch to the face—as her parting gift. To his surprise, she soon becomes a transfer student at his school and his new dormitory roommate, setting the stage for an unconventional living arrangement.

As Wataru navigates life with Rinna and his three other female housemates, he learns that their idyllic island home faces an impending crisis. The local aviation industry, a lifeline for many families, is shutting down, prompting a mandatory evacuation within a year. While Wataru is determined to forge lasting connections with Rinna and the others, Rinna is hesitant, fearing the emotional toll of their eventual separation. Throughout the year, Wataru's unwavering optimism challenges Rinna's resolve, leading them both to reconsider the value of friendship amidst uncertainty.