The God of Poverty, Momiji, is sent down to earth to greet a spoiled high-school girl named Ichiko Sakura, who has had good fortune all her life. Momiji explains that Ichiko has an abnormally high level of good fortune, and is also sucking up fortune from those near her. Momiji attempts to take some of Ichiko's fortune and make her a normal girl, but Ichiko manages to fight her off. The next day, however, Ichiko's butler, Suwano, has a heart attack and is left in a critical condition as a result of Ichiko taking his fortune over the years he served her. Ichiko agrees to let Momiji suck some good fortune out of her, but then she runs off with it and releases it at the hospital, saving Suwano's life. Afterwards, Ichiko decides to sack Suwano from his position so he can live his own life without being at risk. A week later, Ichiko's fortune levels soon return, as does Momiji.

In order to get closer to Ichiko, Momiji transfers into her class, much to Ichiko's displeasure. As Momiji continues to bother her, Ichiko meets Bobby, a perverted travelling priest with the ability to detect fortune energy, giving her an item called the Soumin Shourai, allowing her to manifest her good fortune into various creatures. Momiji responds by manifesting her own monsters out of her misfortune, but they turn out to be useless and she is soundly beaten.

Figuring she needs a boyfriend, Ichiko takes an interest in her sleepy classmate, Keita Tsuwabuki. Upon finding and returning his ID card, Ichiko is invited by Keita to have dinner with his siblings, who are quite poor as their parents had left them. Keita soon takes a strong dislike to Ichiko when she rejects his ideal that being together is more important than money. The next day, Ichiko tries to make up with Keita's brother Ryūta by buying him a super rare trading card. However, he ends up dropping the card down a sewer and gets trapped in there whilst attempting to retrieve it just as a typhoon starts to settle in. As Ichiko is told by Keita how he doesn't want to be in anyone's debt, Momiji makes her aware of the danger Ryūta is in, prompting her to go and save him. As Ryūta gets swept into the river, Ichiko dives in after him, using a device given to her by Momiji to use her fortune to rescue him.

Momiji ends up summoning the masochistic dog god, Momou Inugami, and has him transform into a puppy so he can get close to Ichiko and attempt to steal her fortune. However, Momou finds that getting the fortune off of Ichiko isn't as easy as it looks. As Momou observes Ichiko's behaviour, she notices her personality is different when reading letters from Suwano. That night, as Momou activates a Misfortune Item to spread misfortune, the box containing Suwano's letters falls from the top of the desk, and is thrown away by the cleaners the next day. When Ichiko learns of this, she goes to the trash dump and spends the entire night searching for the box, much to Momou's surprise. Against his better judgement, Momou finds the box for Ichiko. As Momou deduces that Ichiko may not be such a bad person after all, his cover is blown when he reverts to human form, prompting a swift punishment from Ichiko.

Momiji uses an Ageing Box on Ichiko in an attempt to turn her into an old lady, but it instead turns her into a little kid. As Ichiko escapes from Momiji, she encounters one of Keita's sisters, Mika. As Ichiko spends time with Mika in order to avoid Momiji, she encounters Bob and Momou, who tell her she needs to find another Ageing Box to turn her back to her normal age, and manages to get them to search for it. Ichiko then goes over to Keita's home and requests to sleep over whilst trying to keep her identity a secret. The next day, Momiji follows Ichiko as she goes with Keita's family on a picnic and manages to capture her once she's seperated from the others. As Keita tries to search for her, he falls down a cliffside.

Ichiko manages to escape from Momiji only to learn that Keita had gone missing trying to search for her. Realising that Keita had all the things she lacked when she was a child, Ichiko enlists the help of Momou to locate Keita, finding him in a near-death state. As Ichiko tries to revive him, Momiji extracts a small amount of Ichiko's fortune energy so she can save him. Keita awakens the next day with his injuries healed and reunites with his family. As Bobby and Momou manage to locate Urushiyama and retrieve a box from him, Ichiko says goodbye to Keita before meeting up with them and returning to her normal age. However, the experience has left her in a solemn state, only appearing to react to Keita's presence. This turns out to be as she wants to try and return the handkerchief he received from him. After managing to return the handkerchief, she returns to her usual noisy self.

Ichiko is wrongly accused of shoplifting by the police, but she managed to ditch the blame to a tough-looking girl that was passing by. Turns out that girl is Ranmaru Rindou, a new transfer student in Ichiko's class.

Noticing Ichiko doesn't seem to get along with the other girls, Ranmaru tries being friendly with her, but her pride rejects her offer. The next day, a zealous classmate named Akane Tenge and her gang kidnap Ichiko and take her to the old school building with a plan to put her in her place. Ranmaru arrives to rescue her but as Ichiko manages to sneak away, the building collapses with Ranmaru inside it. As Ichiko becomes conflicted over whether to save Ranmaru or not, she recalls when she was younger when her best friend turned against her over a boy, which has haunted her to this day. Telling her to get over her cowardness, Momiji extracts some of Ichiko's Fortune, which Ichiko gives to Ranmaru, allowing her to escape. After the incident, Ichiko lets Ranmaru use one of Momiji's gadgets to learn about her past trauma, which caused her to have a fear of getting close to others.

As the school practises some mixed doubles tennis, Ichiko enters a heated match with Momiji with little regard for their respective partners' safety. Later, as Ichiko tries to teach herself how to cook, another God of Misfortune named Kuroyuri attempts to steal Ichiko's energy as well, but is thwarted by Ichiko's terrible cooking. Momiji soon decides to challenge Ichiko to a match to see who is the better cook, which Kuroyuri is forced to judge.

On a rainy day, Ichiko discovers an abandoned kitten outside her building and decides to take it in, naming it Tama. As Ichiko becomes curious as to why Momiji hasn't been around lately, a toilet god named Ibuki appears before her, but Ichiko refuses to hear him out. The next day, Ichiko learns Momiji has kidnapped Tama and goes to the school gym to confront her. Momiji reveals she was the one who brought Tama to Ichiko's place in order to teach her what it's like to lose someone important. Momiji then goads Ichiko into using the Soumin Shourai and absorbs almost all of her Fortune Energy. As Momiji takes her leave, the gym catches fire, trapping Ichiko and Tama inside without her Fortune to save them. Ibuki then appears, explaining his mission was to save Tama from having what little Fortune she had drained by Ichiko. Offering to save Tama, Ibuki uses a device that can inject Fortune Energy into its target.

With her bath made a mess by Momiji, Ichiko goes with Ranmaru to the public baths, where they are joined by Seiji and his family. The trip proves to be less than peaceful with Bobby and Momou trying to take a peek and Momiji up to her usual tricks. Realising Momiji hasn't had a bath in ages, Ichiko gives her and her familiar, Kumagai, a thorough cleaning. After Bobby makes light of Ranmaru's looks, she ends up busting down the wall between the men's and women's baths, leading to some embarrassing reveals. The next day, Ichiko is surprised to find Momiji with such a radiant personality.

Momiji's spry new personality, which has also extended to Kumagai, is a hit with everyone in school, but Ichiko remains suspicious that it is one of her plots. Momiji explains how, as a result of being washed in the human world, she has lost her powers and changed personality. Ichiko and the others attempt to turn Momiji back to her usual self with no avail. After some initial hesitation, Ichiko soon starts being friends with the new Momiji, finding it pleasantly peaceful. Some time later, Kumagai ends up getting dirty and reverting to normal, teaming up with Momo to try and revert Momiji to normal in the same manner.

Deciding she likes Momiji the way she is, Ichiko grabs her and, with help from Ranmaru and Bobby, they make their escape from Kumagai and Momo on a delivery truck. As they give chase, Ranmaru stays behind to fend off Momo whilst Ichiko, armed with some power enhancing beads given to her by Bobby, fights against Kumagai to allow Momiji to escape. It is her that Kumagai tells her that if Momiji doesn't regain her powers by sunset, she will remain a human forever whilst the old Momiji will die. After some encouragement from Keita, Ichiko catches up to Momiji, who is being cornered on a bridge by Kumagai. As the wind blows Momiji off the bridge, Ichiko catches her, making the decision to drop her onto a garbage boat and return her to her normal self, resuming their love/hate relationship.