Heya Camp△

A girl named Rin Shima comes to a campsite in Motosuko, facing opposite Mount Fuji, to spend the day camping. While setting up a campfire, Rin notices a peculiar girl sleeping by the public restroom, but thinks nothing of it. Later on in the night, Rin once again comes across the girl, Nadeshiko Kagamihara, who had gotten herself lost after just moving to a new house, and shares her curry noodles with her before they both get a clear view of Mount Fuji. After eventually managing to get her sister to pick her up, Nadeshiko leaves Rin with her phone number in the hopes of camping with her once again. A few days later, Nadeshiko begins attending her new school, which Rin also attends.

Nadeshiko pays a visit to her school's Outdoor Activities Circle, consisting of two members; Aoi Inuyama and Chiaki Ohgaki. The girls attempt to put together a cheap tent only for it to break on them. They are helped out by Rin's friend Ena Saitou, who draws Nadeshiko's attention towards the fact Rin also attends her school. Later, as Rin goes on another solo camping trip, Nadeshiko, having been informed by Ena, goes over with some hotpot.

While Nadeshiko makes gyoza hotpot for Rin, Chiaki gets a job at a liquor store to fund the club. Enjoying the meal, Rin apologises for being cold towards Nadeshiko when she invited her to join the club and promises to camp again with her some time. After spending the night in her sister's car, Nadeshiko wakes up early to watch the sun rise over Mount Fuji.

The Outdoor Activities Club plans its first trip, but they do not have the right sleeping bags for the cold weather. Trying to cut costs, the club members try wrapping the summer sleeping bag in foil, bubble wrap, and cardboard, and ultimately decide to each purchase a winter sleeping bag online. Meanwhile, Rin gets her motorcycle license and goes on a solo camping trip in Nagano. On the day of the camping trip, the club members hike through Fuefuki, stopping at a cafe and hot springs resort along the way, and then watching a live stream of Rin.

Nadeshiko's group takes a nice relaxing dip in the hot springs, almost succumbing to the urge to eat before they reach their campsite. Meanwhile, Rin arrives at the Takabotchi Highlands and is overcome by a desire to go to a hot spring too, only to discover the nearest one has closed down. Dejected, Rin decides to climb up the peak, where she is rewarded with a lovely view, before finding a spot to cook some pasta. The club finally arrive at their campsite, where Nadeshiko makes curry for everyone. While the others are asleep, Nadeshiko goes to take a picture of the city lights to send to Rin, who goes to the summit of Mt. Takabotchi to send her a similar view in return.

Rin opens a package to find a mini-grill, which she dreams of using to cook various meats while talking with Ena. Nadeshiko overhears their conversation and suggests a camping trip to try the grill. The two visit a supermarket to buy meat, but are forced to settle for substitutes as their desired items were not available. While there, they meet Aoi, who is working as a cashier, and tell her of their plans. Meanwhile, Chiaki is visiting Lake Shibileko when she encounters a man grilling steak in a skillet, who offers her part of it. Rin and Nadeshiko are driven by the latter's sister to the lake.

At Lake Shibire, Rin and Nadeshiko set up their tents as the latter worries about the myth of a ghost in the lake, while Rin's mother calls the man who had offered Chiaki the steak, revealing him as Rin's grandfather. Rin struggles to ignite the coals in the mini-grill, so Nadeshiko visits a nearby camp for advice. She meets a pair of siblings consisting of a brother and his drunk sister; the brother offers input and new coal for use. After cooking the meat, the two head back to the siblings' campground to give them plates of food as thanks, receiving jambalaya in return. That evening, Rin leaves her tent and encounters a silhouette of a beastly creature, prompting her to run off. As it turns out, the still-inebriated sister had stumbled upon their campsite.

Chiaki shows off a wooden bowl and skillet set to Aoi, which she learns must have the lacquer finish removed in order to place hot food inside and be seasoned, respectively. As they work on this, Ena visits and the three talk about their new substitute teacher and camping after exams. Nadeshiko, Chiaki, and Aoi later visit an outdoor sporting goods store in Minobu, Yamanashi, where Nadeshiko declares her intention to get a job to buy a gas lantern.

Nadeshiko plans to go camping with Rin, but catches a cold the night before and has to stay at home. As such, Rin decides to go on her own to a campsite at Ina, and attempts to take a detour to get there, but finds out that the road is closed. After meeting some mountain climbers, she lets Nadeshiko and Chiaki decide where she goes next, and visits a temple and a hot spring before eating at a restaurant and oversleeping. Meanwhile, Chiaki visits Nadeshiko at home and cooks houtou for her family.

Rin oversleeps and is rushing to her campsite when she encounters a roadblock. Upon being told by Chiaki that it may have been left there and never moved, she proceeds and reaches the site, where she struggles to set up due to the windy conditions. Nadeshiko, Chiaki, and Aoi plan their Christmas camping trip and invite Rin, who initially refuses before being convinced by Ena to accept. Toba, the new teacher, is unintentionally lured into becoming the Outdoor Activities Club advisor and is invited to the Christmas camp. Upon hearing Toba mention bringing beer along, Nadeshiko realizes she was the drunk sister from the Lake Shibire trip.

Chiaki and Aoi check in at the Asagiri Plateau campsite while Toba sets up her grill and starts drinking. While the two eat at a nearby restaurant, Rin prepares her tent and Nadeshiko shows up shortly after. The four purchase firewood and return to Toba's table, where she has fallen asleep as Ena and her dog Chikuwa arrive. The campers and Chikuwa spend the afternoon playing frisbee with other kids before going their separate ways. At night, Aoi cooks sukiyaki for the group. When their stove runs out of gas, Rin leaves to buy more. She remembers Ena's comments about how fun a group camping trip would be, to which she smiles.

Nadeshiko tells the group what she expects them to be like in ten years when Rin returns. After bathing, the campers enjoy various movies and shows on a tablet Chiaki had brought along until they decide to call it a night. Under the stars, Rin and Nadeshiko talk about their plans for the new year before going to sleep. The next morning, the two cook breakfast and watch the Sun rise behind Mount Fuji. Rin returns to her job at a bookstore, while Nadeshiko continues pondering about getting one of her own to afford camping equipment. Ena texts her about a job opportunity delivering New Year's cards, which she accepts. In the epilogue, Nadeshiko returns to Motosuko to solo camp when she receives a message from Rin, who also happens to be doing the same. Nadeshiko proposes sending photos of their respective campsites to one another; after seeing herself in Rin's picture, she turns around and realizes they will be camping at the same location.