Natsu no Arashi!

Hajime and Arashi are hanging out having fun. As Jun observes this, she refers back to the time when she talked to Arashi at the grave site. Jun remembers that Arashi tells her: "I will be gone once summer ends.” Arashi gets asked out on a date by Yamashiro in the meantime. Trusting in their "bond,” Hajime is not fazed by this. Jun believes that Hajime is too carefree about this situation. Thinking that Hajime does not know that time with Arashi is limited, she tells him that he will only be able to be with Arashi in the summer.

On a hot day when mirages are appearing, Hajime and the others are searching for the remote control for the air conditioner. After they search through "Hako-bune," they find a pile of remote controls and start testing them. The one for the air conditioning is nowhere to be found, and it gets hotter and more uncomfortable. As it gets hotter, Kaya notices that Arashi is acting funny, and she becomes scared of her. As the number of remotes to test dwindles, Arashi can no longer bear the heat and goes crazy.

The Master panics, not knowing where she put the ceramic bowl. According to the Master, the bowl that had a bounty of one million yen at "Hako-bune" was gone all of a sudden. Arashi and the others go to search for the bowl using their time leap powers. When they arrive in the past, they find the master just wearing an apron and running around with the bowl. In the end, the master remembers that she had given the bowl to Yayoi for safe keeping, though Yayoi forgets where she placed the bowl.

On a very hot day, the Master comes up with a plan to prepare cold noodles. The staff at "Hako-bune" tries to recreate the amazing cold noodles that Arashi had tried once when she was young. The girls struggle in making the noodles since Kanako and Yayoi have never tried cold noodles, and Arashi does not know the exact recipe either. When it was left up to Kaya, she ended up making noodles topped with shaved ice. On the other hand, Arashi ends up creating a Neapolitan. It takes a turn for the worse when they start running the noodles in the rain gutter.

During her shift at "Hako-bune," Kanako, all of a sudden, gets dizzy and drops the salt shaker. When Kanako borrows some glasses from Arashi, she is surrounded by a bright light, transforming her into a maid warrior. Disregarding how Kanako feels, Hajime and the others, wanting to see her transform again, try to get Kanako to wear the glasses again. All of a sudden, "Hako-bune" has turned into a cosplay party for the girls.

One day in the pouring rain, Yayoi and Hajime take the day off from work at the cafe and go over to Jun's house where Kaya is staying. Jun finds out that Hajime is coming over and panics to conceal her secret. In the midst of her panicking, Jun ends up wearing a wedding dress. Jun finally finishes hiding her underwear and such, though she forgets to hide the family portrait at the front door. As she dashes to the front door to get the portrait, the door opens, and she falls into Hajime with her wedding dress still on...

Sucked of his life essence on a daily basis by Yayoi and Kanako, Sunglasses is somewhat groggy. Arashi proposes that only one of them use him as a source of energy supply, so Yayoi tries to find someone compatible with her from today's customers at Hakobune. Since Yayoi is shy with men, she struggles to respond back to them. With his dog, Yamashiro arrives at the café. Everyone at Hakobune urges Yayoi to go talk to Yamashiro, but, panicking, Yayoi runs away.

After having fun at the beach, they came to an inn. They enjoyed themselves by going to saunas, outdoor hot springs, and playing mahjong. With Arashi's "kindness," Jun ends up sharing a room with Hajime. To keep her secret, Jun ends up buying men's underwear, and avoiding the bath. But in the end, Jun gets caught by Hajime and gets dragged to the bath. Arashi and Kaya save Jun. With Arashi's proposal, they end up doing a courage test. Arashi and Jun coincidentally pair up. Jun asks Arashi how she feels about Hajime.

One day, everyone gathers at Cafe "Hako-bune", where Arashi and Hajime are working, and they discuss about the summer tradition. They end up planning to go to the beach, and Hajime is overjoyed because he will be able to see Arashi in her swim suit. Arashi, Kaya, Yayoi, Kanako are all having fun choosing swimsuits from Master's collection. But Jun, misunderstood as a boy, is having a hard time trying to keep his cover. The following day, they go to the beach in Yamashiro's car. Drawing men's attention, playing with the creatures, each one of them enjoys their summer.