"Doraemon: It's Summer!" is a short anime film that centers around Nobita Nobi, a young boy who often struggles with schoolwork, sports, and daily life. The story begins with Nobita feeling overwhelmed by the summer heat and his lack of motivation to complete his summer homework. Doraemon, a robotic cat from the future, steps in to help Nobita by using his futuristic gadgets. One such gadget is the "Summer Holiday Set," which allows Nobita to create a miniature summer resort in his backyard. This resort includes a beach, a pool, and even a small island, providing Nobita and his friends with a perfect summer escape.

As Nobita, along with his friends Shizuka, Gian, and Suneo, enjoy their makeshift summer paradise, they encounter various adventures and challenges. The group explores the island, engages in playful activities, and faces minor conflicts that test their teamwork and friendship. The narrative emphasizes the carefree and joyful spirit of summer, highlighting the importance of friendship and creativity.

Throughout the story, Doraemon's gadgets play a crucial role in driving the plot forward, often leading to humorous and unexpected situations. Despite the occasional mishaps caused by Nobita's clumsiness or overreliance on the gadgets, the group ultimately learns valuable lessons about responsibility and perseverance. The film captures the essence of childhood summers, blending lighthearted fun with moments of personal growth for the characters.