Kaede Mizuno is a main character in the series and serves as the primary love interest for the protagonist, Junpei Kōsaka. She is introduced as Junpei's classmate and the object of his longstanding affection, though she is initially completely unaware of his feelings for her. Their first meeting occurred during their first year of high school when Kaede was trying to rescue a kitten stuck in a tree. She slipped and fell, landing directly on Junpei, and then tried to wake him up by repeatedly slapping him. Together, they sought someone to care for the kitten, nearly arriving late to their entrance ceremony. It was during this ceremony that Junpei was surprised to see Kaede take the stage as the first-year representative, revealing that she had achieved the highest score on the prestigious school's entrance exam.

Kaede has a complex and contradictory personality. She is athletic, serving as a star member of the school's track and field club, and is academically brilliant, but she also has a notably airheaded and naive disposition. She tends to take comments directed at her very literally, which often leads to misunderstandings with Junpei and others. For example, she once misinterpreted a frustrated yell from Junpei meant for arguing cats as being directed at her. She is also described as being very sincere and taking things to heart, reacting to situations with a charming innocence.

Her most defining trait is her profound love for cats, which ironically creates problems for Junpei due to his severe cat allergy and curse. Despite her affection, cats tend to avoid her. This is because her family owns four large military dogs, including a Bernese Mountain Dog, a Labrador, a Husky, and a German Shepherd, and she carries their scent with her. Furthermore, her inexperience with cats, having grown up only with dogs, leads her to handle them with an overenthusiasm that borders on being rough, causing the local park cats to consider her their archenemy. She once devised a plan to capture cats by laying down food, only to pet them too intensely, which made them neurotic. She does, however, stop and apologize for this behavior when Junpei explains the issue. Aside from animals, Kaede has a unique fascination with yakuza and mafia culture, enjoying media with strong "manly spirit".

As the story progresses, Kaede's role evolves from being merely the subject of Junpei's crush to developing her own romantic feelings for him. She begins to hope for a closer relationship with Junpei but often holds back because she becomes wary and saddened by his close relationship with their mutual friend, Kanako Sumiyoshi, whom she mistakenly believes is dating Junpei. This misunderstanding acts as a major barrier to her acting on her own feelings. Her main motivation, aside from her school and athletic activities, is navigating these growing personal feelings while remaining largely oblivious to the supernatural curse that complicates Junpei's life.

Notable abilities include her exceptional physical prowess, particularly in running, where her speed and endurance far exceed that of an average person, including Junpei. This athletic ability is a result of her dedication to the track and field club. Her academic intelligence is also a significant, though often understated, ability, as demonstrated by her high score on the high school entrance examination. No reliable direct information exists concerning her development after the events depicted in the anime.