Hariham Harry, often called simply Harry, is a central figure in his story as a fairy from a devastated future timeline. He belongs to the Harihari clan, a race of rodent-like beings from a place called Harihari Township. Originally, he lived there peacefully with his close friends, Listol and Bicine. However, their home was struck by a mysterious and deadly epidemic. Desperate to save their infected clan members, Harry and Listol joined the Criasu Corporation, the organization that would become their enemy. This decision proved tragic, as Criasu deceived them and ultimately destroyed their hometown. Realizing the corporation's treachery, Harry fled to the present day, seeking a way to change the future. He escaped while caring for a mysterious baby named Hugtan, who is the de-aged form of Cure Tomorrow, a hero from the future for whom Harry holds deep feelings.

In his natural form, Harry is a small, hamster-like fairy with orange and cream-colored fur, a distinctive tuft of red hair, and brown eyes with red markings. He always wears a gold chain necklace and a light blue pearl earring. When necessary, he can transform into a handsome young man with messy red hair and blue eyes, dressed in a white t-shirt, a black leather jacket, and jeans, while still retaining his chain and earring. This ability to assume a human form allows him to interact more freely in the present world, where he opens a fashion and goods shop named Beauty Harry, which serves as a base for the main characters.

Harry's personality is defined by a blend of confidence and deep-seated care for those around him. He is often self-assured and can come across as boastful, particularly about his handsome human appearance, and he has a known sensitivity to being mistakenly called a mouse, insisting he is a harriham. He speaks in a distinctive Kansai dialect, which adds to his character. Despite his proud exterior, he is fiercely loyal, highly supportive, and deeply protective of his friends, especially Hugtan. His primary motivation is to atone for his past alliance with Criasu and to secure a bright future for Hugtan and the world. He acts as a mentor to the Pretty Cure warriors, using his knowledge of the future to guide them and protect Hugtan, who is essential to saving their timeline.

His key relationships drive much of his personal story. His bond with Hugtan is the most significant; he serves as her caretaker and protector, and her existence is directly tied to Cure Tomorrow, for whom his feelings run deep. With Homare Kagayaki, one of the Cures, he shares a complicated dynamic. While Homare develops an unrequited crush on him, Harry, though supportive and caring, cannot return her romantic feelings and instead offers her steadfast friendship. His past friendships with Bicine and Listol are fraught with pain. Both former friends were corrupted by Criasu and become antagonistic, Bicine developing an obsessive fixation on Harry. These conflicts force Harry to confront his past directly. His relationship with Listol, in particular, reaches a climax when Harry must face a friend who no longer remembers him, leading to a final act of empathy that helps redeem them both.

Throughout the narrative, Harry undergoes significant personal development. A central aspect of his character is the monstrous transformation he undergoes when overwhelmed by despair. The gold chain he wears is not just an accessory; it is a seal that suppresses this feral, destructive form, which was first unleashed due to the trauma of his past. Initially, he is ashamed of this part of himself and relies on others, like Cure Tomorrow and Cure Étoile, to calm him down. However, his growth culminates in a moment of profound change when he voluntarily removes his own chain during a final confrontation. Rather than succumbing to his inner monster, he masters his despair and uses empathy to reach out to a lost friend, demonstrating that he has learned to accept and control his darkness.

As a fairy, Harry possesses notable abilities beyond his dual forms. He is capable of fighting, displaying agility and combat skills in both his hamster and human shapes. He can also conjure defensive barriers and harness a power known as Tomorrow Power, which he uses to support the Cures in battle and even restore his own broken chain. His role as a mentor and strategist is as vital as his combat prowess, making him a key figure in the fight to protect the future. Following the final battle, Harry returns to a reformed future, reuniting with his redeemed friends and watching over the next generation, finally at peace.