Kono Aozora ni Yakusoku wo: Youkoso Tsugumi Ryou e  

この青空に約束を― ～ようこそつぐみ寮へ～, この青空に約束を― 〜ようこそつぐみ寮へ〜

One morning, Wataru Hoshino stumbled upon an unconscious girl in his room. She was only wearing underwear. When she woke up, she hastily escaped by jumping out of a window before attacking Wataru and punching him in the face. The girl turned out to be Rinna Sawaki, who later became a transfer student at Watarus school and shared a dormitory room with him. Wataru lives with four other girls and their teacher in a dormitory on South Sakojima Island. However, due to Temizugawa Heavy Industries' cancellation of its aviation branch, the families associated with the corporation must evacuate within one year. As a result, the four girls will have to leave the island in that time frame. Rinna is hesitant to form friendships with Wataru and the other girls due to the emotional pain she may experience as a result of their eventual separation. However, Wataru disagrees with her perspective and tries to convince her otherwise throughout the year.