Upon returning from school one day, Ohana Matsumae learns that her mother is going on a moonlight flit with her boyfriend to escape from debt and they are sending her to live at her estranged grandmother's hot spring inn in the country. When her best friend, Kōichi Tanemura, hears of this, he confesses his love for Ohana before running off, not seeing her off when she leaves. As Ohana arrives at the Kissuisō inn, she makes a bad first impression with one of the employees, Minko Tsurugi, before being informed by her grandmother, Sui Sujima, that she is to work at the inn to earn her keep. She is shown around the inn by the head mistress, Tomoe Wajima, and another employee, Nako Oshimizu. When Ohana notices the hard work Minko has to do, she tries to do something nice for her by airing out her futon, but it ends up falling off a window and landing near some customers. As Minko is slapped by Sui for Ohana's mistake, Ohana demands to slapped even harder, though Minko doesn't particularly thank her for it.

Sui instructs Nako to train Ohana to become a housekeeper, though she is quite shy about it. When Nako has to attend to another duty, Ohana, having been taught to only rely on herself, she cleans another room where the author Tarō Jirōmaru is staying by herself. When the staff's breakfast is cancelled due to an error by Minko in the kitchen, Ohana makes breakfast for everyone, though this only serves to irritate Minko further. Afterwards, Tarō complains that some drafts for his story have gone missing from his room which Ohana had cleaned earlier, having not been informed by Nako beforehand. After Sui instructs the others to go to resume their duties rather than search for the draft, junior chef Tōru Miyagishi takes Ohana to pick up some luggage. As Tōru mocks Ohana's ability to take care of herself, Ohana inadvertedly tells him to 'die' which nearly causes him to crash. Feeling guilty about it and taking a walk to reflect upon herself, Ohana decides to speak her mind against Minko and Nako, wanting to cook them their least favourite foods tomorrow as payback. The next day, Ohana finds some of Tarō's discarded works, which turn out to be erotic stories using her as a character.

Minko and Nako discover Ohana has gone missing, as she has been confined by Tarō, who admits he was trying to come up with a sex novel to pay his hotel bill. When he discovered by Nako and the others, he attempts to make a run for it by stealing one of the inn's vans, so the staff give chase. They eventually find him at a seaside cliff where he jumps into the sea, but Nako manages to save him from drowning. As Tarō laments his lack of talent, Ohana tells him that, even though his novels were perverted, they showed a side of Ohana she never knew before. Afterwards, they arrange for Tarō to work at the inn to pay off his bill, and Minko eats the revenge meal Ohana prepared for her. Later that night, Ohana finds notes Minko wrote on devising an alternative insult to 'die', and also receives a text from Kōichi.

The first day of the school trimester starts for Ohana, Minko and Nako, and Ohana soon finds herself popular with the other students in the class, including Yuina Wakura, who works at a rival hot springs inn, the Fukuya Inn. As Ohana tries to figure out how to respond to Kōichi's text, she and Nako go to the Fukuya Inn concerning the neighbourhood watch where they encounter a grey heron, before visiting a temple, where Nako talks about how she wants to get rid of her timidness. Later, Ohana learns that Minko actually has a crush on Tōru. As Ohana tries to apologise to Minko about it, they both witness Tōru picking up Yuina on his motorbike.

As Minko continues to be downhearted from the other day, she overhears Ohana, Nako and Tomoe talking with Tarō, who claims Tōru had been scouted by Fukuya Inn. Tomoe reveals to Ohana that it was Tōru that allowed Minko, who wanted to become a chef, to work at the Kissuiso. After a failed attempt to try and get Minko to show her true feelings, Ohana goes by herself to the Fukuya Inn, where she learns from Yuina that Tōru was simply filling in for an absent chef for the day, and she herself only wanted to have a ride on his motorbike. Afterwards, Minko allows Ohana to call her by her nickname, whilst Ohana finally responds to her text from Kōichi.

Kissuiso is visited by a management consultant named Takako Kawajiri, wanting to revitalize the inn by having the mistresses wear new outfits. However, attempts to dress Ohana and Nako up in new outfits fares badly with the customers. After Takako takes her leave, Ohana's uncle, Enishi Shijima, feels downhearted that his efforts to help the inn are always rejected by Sui. As Ohana feels she should do something to help improve business, the janitor, Denroku Sukegawa, takes her to a secret room filled with old uniforms made by Sui over the years. Ohana and Nako decide to give these a try, which proves to be a hit with the customers.

Tomoe is pressured by her mother to attend a marriage interview in a week. Meanwhile, the Kissuiso pays host to a group of rowdy 'survival gamers' who take their roleplay very seriously and cause various troubles for the employees. Planning to quit her job and return home, Tomoe decides to try and drive the gamers out and get fired. However, her attempts to irritate the gamers have the opposite effect, responding well to the gamers and making her appreciated by the other employees. As a result, Tomoe decides not to return home as she enjoys working at the Kissuiso.

Ohana learns from Yuina that the Fukuya Inn is to be featured in a magazine, taking on a mystery guest. Meanwhile, the Kissuiso gets a sudden surge of customers with Nako and Tōru on their day off, but as Sui prepares to put in her share of the work, she suddenly starts feeling pain and is taken into hospital. After Ohana is told to return to work, she gets a call from Kō, who tries to tell her he is on his way to visit her, but she is unable to hear it. Arriving back, the staff, along with Takako, suspect that the inn may be hosting mystery guests from one of the magazines, suggesting that they prioritize their service over the other customers. However, after finding Sui's accounting book, Ohana stands up against her, saying that all customers need to be treated equal. Needing extra support to deal with the large number of customers, Ohana calls in Nako before going off to find Tōru, who is attending a wedding.

Ohana ends up finding Tohru with the encouragement from Kōichi. He tries to book a stay in order to see Ohana except the rooms were full and he went home. Tohru says that if Ohana thinks he could solve the problem at Kissuiso, then he'll just have to fix it. In the end, they pull through and tend to every customer. A woman and her grandmother were actually the people who were from the magazine and due to Ohana's motto that every customer is equal, Kissuiso received a good rating.It was seen at the end that the Manager came back from the hospital.

As a result of constantly getting up early to help clean, Ohana collapses with a fever and is told to rest for the day. Tōru makes her some porridge and becomes slightly enamoured by her solemn appearance. Minko starts to become a bit jealous of the attention Tōru gives to Ohana. As various members visit Ohana and tell her to stay in bed, Ohana gets a strange dream where she is at the temple and Kō appears telling her to come back, Kissuisō doesn't need her. There is a little girl and a young fox hiding while watching Ohana. This dream worries Ohana about whether the Kissuisō even needs her. However, just as she is writing out a text to Kōichi about possibly going home, Minko and Nako convince her that she's still needed. She falls asleep and finds herself in the dream again where she tells Kō that she wants to stay at Kissuisō. The little girl and the young fox can still be seen watching her during the dream.

After the Kissuisō gets a scathing review in a magazine, it becomes apparents that all the hot spring inns in the area are receiving poor reviews whilst a newly constructed hotel is being praised. Wanting to get to the bottom of this, Ohana heads to Tokyo to find out who's responsible for the review, which turns out to be her mother, Satsuki. She reveals she wrote a poor review under orders from higher ups, which annoys Ohana, who had been bottling up her annoyances with her. When Satsuki refuses to go to Kissuisō to give her true opinion, Ohana decides to stage a protest. Whilst doing so, she decides to visit Kōichi, only to notice another girl seemingly attached to him. After hearing from Kōichi that the girl has an unrequited love for him, Ohana feels guilty and runs off into the rain in tears, but is found by Minko and Tōru.

After spending the night at a hotel with Minko and Tōru, Ohana suggests that they kidnap Satsuki and force her to come to the Kissuisō, with Tōru only agreeing if they take Kōichi with them as well. Whilst Minko and Tōru visit Tokyo's various restaurants, Ohana runs into Igarashi, who tells her that she needs to decide what her feelings for Kōichi are. After she gets a call back from Kōichi, who tells her about how he visited the Kissuisō whilst Ohana was searching for Tōru at the time, Ohana feels guilty and decides not to take Kōichi back to the Kissuisō with her. After joining up with Minko and Tōru, the group goes to see Satsuki, who decides by herself to go to the Kissuisō. When Tōru's asks Satsuki about why she changed her mind, she replies that it's because Ohana reminded her of herself when she was younger.

The staff members of Kissuisō wait and try to mentally prepare for Satsuki's arrival. Sui places Nako in charge of taking care of Satsuki, while the others speculate on whether or not that is a good idea. Arriving, Satsuki comments on how the inn hasn't changed at all from her years as a child, and criticizes constantly on how everything is done. However, Sui states that, in order to properly satisfy a customer that one must observe them on their first stay to see what that customer prefers, adding that even though it is Satsuki's first stay in the inn, it is not her first time being there. Sui and Ohana work together to make a list of what Satsuki likes. After a night of drinking, Satsuki, Ohana, and Sui all begin to understand each other a little better, and Satsuki leaves the next morning after writing a new, positive and praising review of Kissuisō. Ohana sorts out her feelings about Ko and, after a tearful realization, shouts her thanks to him for watching over her and says her farewells.

Ohana's school goes on a field trip to another hot spring inn, run by Yosuke Himawari, who is Yuina's distant relative and her alleged fiancé. They visit the beach, where a boy who was previously turned down by Minko before tries his luck again. Later than night, Ohana and Nako overhear Yosuke asking Yuina if she wanted to come work at his inn when she graduates. The next day, a group of part-timers working at the inn decide they want to quit. As Yosuke becomes irritated by this, Yuina tells him that people will only do things they enjoy doing, declining Yosuke's offer of running his inn.

The inn becomes troubled over becoming shorthanded, but reject Ohana's offer to help out. However, she feels she needs to do something and, after the inn becomes unable to find replacement waitresses, they accept Ohana's help, with Minko and Nako deciding to help her out as well. However, the robotic system that assists with dishes breaks down, so Ohana suggests that they send the customers to have a bath before dinner to give them extra time to set up the tables. As Ohana and the others work on the tables, getting help from the other students, Yuina visits Yosuke and, after hearing that he might want to marry someone like Ohana, decides to break her habit of not working and help him clean the baths. After dinner, Yosuke allows the girls to use the hot springs. As the field trip comes to an end, Yosuke decides to rethink his training whilst Yuina decides to work harder herself.

Enishi brings in Tetsuo Inashi, a movie producer who wants to film in Yunosagi and use the Kissuiso as a locale for a movie, and to his surprise, Sui allows him to do as he pleases. The next day, the lead actresses are brought in, whilst camera tests are held and Ohana and co. are asked to clean a pool. As work progresses, Enishi laments how he always felt Satsuki was more suited to work at Kissuiso than he was.

Satsuki calls Sui, warning her that there might be something fishy about the film crew. The next day, they hear the project has been called off, putting Enishi in a tough spot as he had paid them a lot of money. Satsuki later calls him, telling him that the director was a scam artist trying to pay off his debts. As Enishi and Takako argue over the incident, they fall into the pool together and reconcile. After Sui explains her situation to the neighbourhood association, she commends Enishi for his defense of Takako.

Nako has always been worried about her personality, which falters outside of her home. As Nako gets a larger bonus on payday, she becomes worried that she needs to change in order to deserve that amount. Later that day, she, Ohana, Minko and Yuina go shopping, where she ends up splashing out in the hopes of changing, though doesn't feel she has at the end of the day. The next day, Nako decides to go to work with the same attitude she has at home, but it ends up backfiring against her. When she asks Sui about why she got a high bonus, she explains it was as thanks from a customer who followed her advice, praising her for the personality she has at Kissuiso, which cheers Nako up.

As a school festival approaches, Ohana's class decides to do a Princess Café, assigning Yuina and Minko in key roles, whilst Nako's is put on the festival commitee. Hearing that Tōru is planning to visit, Minko decides to take her position in the cooking department seriously. However, Minko angers the other members of the food team when she rejects their request for rice omelette, so Minko decides to do everything herself.

It's the day before the school festival so Minko wakes early, buys the ingredients, and starts prepping with the unwanted help of Ohana. When Nako asks to have omelette rice for lunch, Minko, unfazed, makes a perfect omelette rice dish. Adding Ohana's twist to the dish, they decide to also serve it on the menu of Class 2-A's princess cafe. Tōru arrives and Minko adds a big ketchup heart around his omelette rice. After they see from the class building that the campfire was lit, Minko, Ohana, Yuina, Nako, and her classmate decide to go down and take a look.

Enishi and Takako announce they are getting married, with Sui insisting that they hold a proper marriage ceremony. With costs looking high, Ohana suggests that they hold the ceremony at the Kissuiso, with everyone else offering to pitch in. As Tōru takes Minko to the beach to calm her nerves, she becomes disheartened when he brings up Ohana out of the blue and starts lashing out at her again like she used to. With Takako concerned about the cost of the ring and willing to call off the wedding, Sui gives her her old weddding ring, telling her about how she and her husband got married. She entrusts Enishi's happiness to Takako, but states she does not intend to pass down the inn to her.

As preperations for Enishi and Takako continue, Ohana gets a call from Satsuki, who talks about the one-sided love she had for Ohana's late father, and decides to continue her own one-sided crush on Kō. Later, as Minko continues her antagonistic attitude towards Ohana, the two end up fighting, during which Tōru overhears about Minko's crush on him. He then comforts her, admitting that he has a liking for Ohana, but still holds Minko's feelings in regard. Minko decides she won't give up on her crush on Tōru and makes up with Ohana, allowing Enishi and Takako's wedding to go smoothly. After the wedding, Sui announces that Denryoku is planning to retire from Kissuiso and that his logs, along with Kissuiso, will be sealed up.

As Ohana contemplates what she should do if the Kissuiso closes down, Sui asks her to go to Tokyo alongside Takako, who wants to try and reclaim the money Enishi lost. Meanwhile, Satsuki encounters Kō, who reveals that he hasn't dumped Ohana and wants to know more about her. Satsuki then takes him to her office where she shows him footage from the cancelled film so he can see how she works at the Kissuiso. Upon arriving in Tokyo, Ohana and Takako manage to locate and apprehend Inashi. Afterwards, Ohana and Kō run into each other.

After spending some time with him, Ohana invites Ko to come to the Bonbori Festival before leaving Tokyo again. As Ohana arrives back at the Kissuiso, they start getting a flood of reservations thanks to a positive review written by Satsuki. However, Sui insists that she intends to close the Kissuiso down after the Bonbori Festival. The next day, Sui takes Ohana with her to visit her husband's grave, where Sui suddenly collapses. Sui explains that she wanted to close Kissuiso down so the others could do what they want. Upon returning to the Kissuiso, the others are at odds against Sui, with only Ohana offering to help out with the Bonbori Festival preparations.

With the growing number of reservations, Ohana grows concerned about the changes Kissuiso is making and the lack of sleep the employees are getting. She is also finds herself at odds with some of the others for siding with Sui. Ohana tells Nako about what Sui told her, who tells her why her opinion differs. Things turn bad for the Kissuiso when Tomoe sprains her ankle on the day before the festival, but Sui and Satsuki arrive to fill in as waitresses and together they manage to make it through the day of the festival. Afterwards, everyone goes to the Bonbori festival.