Hinata teaches Aoi how to pitch up a tent for a camping sleepover with Kaede and Kokona in Hinata's garden. After eating dinner and taking turns in Hinata's bath, the girls spend time in the tent having all sorts of conversations.
After accidentally stumbling upon a view of Mt. Fuji herself, Aoi tries to keep it a secret from the others as they carry on up the mountain. With the path becoming tougher to climb, Aoi struggles but receives encouragement from Kaede.
Aoi becomes angry with Hinata after she accidentally pulls her skirt down and later ruins something she was knitting, refusing to talk to her the next day.
After hearing from Hinata's father about how he watched the sunrise from atop a mountain during high school, Aoi decides she wants to climb Mt. Fuji at night. Finding a down jacket to be too expensive, Aoi tries to borrow one from her mother, only for her to refuse to let Aoi go climbing out of concern for her safety.
Hinata takes Aoi to visit Azuma Gorge, suggesting they invite Kaede and Kokona along to go swimming in ''sexy'' swimsuits. Aoi, who only has her school swimsuit, tries to pick out a swimsuit for herself.
The girls make their preparations for the Mt. Fuji climb, with Kaede advising the girls to bring plenty of snacks to fuel themselves. After buying some snacks with Hinata and Kokona, Aoi starts to become nervous if she'll be able to climb Mt. Fuji.
Arriving at Mt. Fuji's fifth station, the girls take some time to get some lunch and explore the stores before beginning their ascent. As they continue to progress, the climb gets progressively harder and Aoi starts feeling more and more tired, but remains determined to see the climb through.
As the girls approach the 8th station, Aoi is overcome by tiredness and headaches from pushing herself too hard. Believing Aoi has developed altitude sickness, Kaede decides to stay behind to look after her while Hinata and Kokona go on ahead.
As summer vacation begins, Aoi remains depressed from her failure, with Hinata unsure about how to help her. Upon receiving some postcards Hinata and Kokona sent her from Mt. Fuji's summit, Aoi decides to take a walk up Mt. Ternran, the first mountain she climbed with Hinata.
After being invited to go firefly watching by Kokona, Aoi and Hinata recall that they once went firefly watching when they were younger. When they ended up getting lost, they were led back to their parents by an alleged firefly, though they both have different ideas about what kind of firefly it was.
With Aoi's mother still cautious about her climbing up mountains again, Hinata and her father suggest that she invite her to climb Mount Kirigamine with them. Whilst climbing the mountain, Aoi is reminded of the mountain she climbed with Hinata when they were younger, though neither can remember which mountain it was.
Aoi is anxious about climbing Mount Tanigawa as it involves riding a cable car, which isn't good for her fear of heights. Later, Kaede invites the girls to her house, where she explains she too was scared whilst riding a cable car, but found it less scary on her second go.
Having made much progress in her preparations for the Mt. Tanigawa trip, it soon dawns on Aoi that she hasn't touched her summer homework. With Hinata on vacation, Aoi asks Kaede to help her out.
On the day before the Tanigawa climb, Kokona, whose birthday is on the same day, gets some new shoes as an early present from her mother and decides to go on a walk to Akebono Children's Forest Park to try them out.
The day of the Mount Tanigawa climb finally arrives, with Hinata also pondering what will happen after she and Aoi fulfill their dream. After a series of staircases and some obligatory forms, the girls arrive at Tanigawa, where Aoi must face the cable car first hand.
As the girls start climbing up the mountain, they encounter a quiet young photographer named Honoka, who had previously helped them by the cable car. Interested in her, Aoi decides to follow Honoka as she goes about her photography.
The girls have Honoka join them for dinner, where they celebrate Kokona's birthday together. Later that night, Honoka gives some advice to Aoi concerning her promise. The next morning, as the girls continue their ascent, Aoi and Hinata look back on their recent adventures as they finally watch the sunrise together.
On the day the Aoi invites Honoka to join her and the others for a fireworks festival, she and Hinata get into an argument with each other. As Aoi takes Honoka on a tour of Hanno, she can't stop thinking about Hinata and decides to try to make up with her, while Hinata hear how Aoi feels about her from Hikari and decides she should apologize too.
