Ichiko Sakura is a sixteen-year-old high school student who serves as the central character of her story. She is a girl of remarkable fortune, blessed with beauty, intelligence, wealth, and athletic prowess, seemingly lacking for nothing. Her life has been one of uninterrupted good luck, a fact she takes for granted and which has shaped her into a person who is initially self-centered, arrogant, and emotionally detached from her peers. Born on April 16, she stands 157 cm tall and carries herself with the confidence of someone who has never truly faced hardship, often using her charms to manipulate situations to her advantage.

However, this immense good fortune is not without a significant cost. Ichiko naturally and unconsciously absorbs "happiness energy" from the people around her, draining their luck to fuel her own. Unaware of this phenomenon for most of her life, the consequences become dire when her long-serving butler, Kikunoshin Suwano, nearly dies from having his fortune drained away by her. This event serves as a critical wake-up call, forcing her to confront the negative impact her very existence has on others. The revelation that her perfect life is built upon the misfortune of those nearby, including the people she cares about, plants the first seed of change in her personality.

At the start of the narrative, Ichiko embodies a textbook example of a spoiled and lonely individual. Her past experiences, particularly a traumatic betrayal by a childhood friend in grade school, have caused her to build a protective emotional barrier, leading her to dismiss the value of friendship and view relationships as transactional. She is a skilled actress who presents a facade of a perfect, kind girl in public, but her true personality is far more fierce, prideful, and explosive, surfacing whenever she is provoked or her pride is wounded. She has a strong aversion to being called by her last name in a teasing manner and is particularly sensitive about her large bust, hating the nickname that plays on this feature. Despite her many talents, she has one notable weakness: she is a hopelessly terrible cook.

Her primary motivation is initially to protect her charmed life and maintain her status and comfort, which puts her into direct conflict with the poverty god, Momiji. Momiji is dispatched to the human world to steal Ichiko's excess fortune and restore the world's karmic balance, and their ensuing rivalry is the engine of the plot. While Ichiko and Momiji start as bitter enemies engaged in comedic, over-the-top battles, their relationship deepens considerably. Through constant conflict and forced proximity, they develop a bond that transcends hatred, becoming something akin to bickering family who care for one another deeply, even if neither would readily admit it. This relationship is the catalyst for Ichiko's growth, forcing her to re-evaluate her priorities and confront her own loneliness.

Ichiko's journey is defined by a slow but significant development. She gradually learns to lower her emotional defenses and open herself up to genuine connections, forming key relationships with other characters. She develops a close friendship with her classmate Ranmaru Rindou, a tough and kind-hearted girl who initially sees through Ichiko's cold exterior, and she becomes the object of affection for the kind but impoverished Keita Tsuwabuki. Through these relationships and her constant battles with Momiji, Ichiko is repeatedly placed in situations where she must choose between her selfish desires and the well-being of others, leading her to perform selfless acts that demonstrate a growing empathy.

In terms of abilities, Ichiko's primary power is her innate, overwhelming fortune. This luck is so potent that it can be weaponized, allowing her to avoid harm and succeed in almost any endeavor. She later receives a magical item called the Soumin Shourai from a wandering monk named Bobby, which allows her to physically manifest her happiness energy. By using this artifact, she can summon small, powerful creatures based on the Chinese zodiac, turning her abstract fortune into a tangible force for combat and protection. Despite her seemingly delicate appearance, she is also an incredibly proficient fighter, possessing skills in various forms of martial arts and showing great physical strength when necessary. By the end of her story, Ichiko remains a proud and strong-willed girl, but she is no longer the isolated and purely selfish person she once was, having learned that true happiness is found not in fortune, but in the bonds she shares with others.