Honoka Yukishiro is one of the two main protagonists from the anime series in which she appears. She is a student at Verone Academy, starting as a second-year and later advancing to her third year. Known for her exceptional intelligence, she is the top student in her class and an active member of the school's science club. Her classmates have given her the nickname the Queen of Knowledge due to her vast erudition. Despite her academic prowess, she also possesses a somewhat air-headed and curious side, often conducting various experiments after school.

Honoka lives in a large, traditional Japanese-style mansion with her beloved dog, Chuutaro, and her grandmother, Sanae Yukishiro. Her parents work overseas as art dealers and are frequently absent, typically returning home only once a year to celebrate her birthday. This living arrangement has fostered a gentle and polite demeanor, shaped by her grandmother's doting care.

Her personality is defined by a blend of kindness, selflessness, and a strong sense of responsibility. She is a gentle and understanding individual who consistently places the happiness and well-being of others before her own. However, this kindness is balanced by a surprisingly strict and forceful side. When she believes someone is not putting forth their best effort or is acting in a way that is wrong, she can become quite intimidating and will lecture them until they correct their behavior. This intensity emerges from a place of genuine concern for their growth. Similarly, while she is the object of affection for many boys at school, she shows little romantic interest in them, preferring to maintain platonic friendships.

Her role in the story begins when she discovers a shining box containing a mysterious cell phone, leading her to partner with the fairy Mipple. This partnership allows her to transform into Cure White, the Emissary of Light. She is initially unaware of her classmate Nagisa Misumi, but after they are both chosen to become Pretty Cure, they are forced to work together. Honoka approaches her duty with a positive and inquisitive mindset, viewing it as an exciting and interesting opportunity, in contrast to Nagisa's reluctance. As a warrior, she embodies the yang principle of light and activity, complementing Cure Black's yin powers of darkness and physicality.

Key relationships are central to her development. Her partnership with Nagisa Misumi is the most significant. Initially, they have little in common and keep a formal distance, but after a major fight and reconciliation, they become irreplaceable best friends who call each other by their first names. Honoka admires Nagisa for her courage and cheerful nature. She also forms a deep bond with a boy named Kiriya, who is an enemy from the Dark Zone. She takes it upon herself to teach him about human emotions and kindness, showing great patience and care. When his true nature is revealed and he ultimately perishes, Honoka experiences profound grief and sadness, a loss that continues to affect her for some time. She later becomes a mentor-like figure to Hikari Kujou, treating her with a protective and nurturing attitude.

Honoka undergoes significant personal development throughout the series. She evolves from a socially reserved girl with few friends, partly due to her strict nature intimidating others, into a young woman who deeply values her bonds of friendship. She learns to open up and trust Nagisa completely. She also experiences loss and grief through her relationship with Kiriya, maturing emotionally as she learns to navigate these complex feelings. Her intelligence is not just an academic trait but is applied strategically in combat and to solve problems, demonstrating her growth as a reliable and capable individual.

As Cure White, her abilities and fighting style are distinct from her partner's. While Cure Black relies on brute strength, Cure White fights with grace, agility, and technique, often using kicks and judo-like moves to throw much larger enemies. Her signature finishing moves are typically performed in conjunction with Cure Black. Their most notable joint attack is the Marble Screw, where she summons white lightning and combines it with Cure Black's black lightning to form a powerful stream of energy. Other collaborative attacks include the Rainbow Therapy, which purifies evil influences, and the more powerful Rainbow Storm, enabled by the Rainbow Bracelets. In the sequel, Max Heart, she gains upgraded abilities such as Marble Screw Max and can perform team attacks with the third Cure, Shiny Luminous, like the devastating Extreme Luminario. In her civilian form, she maintains her intelligence and curiosity, aspiring to one day become a scientist and win a Nobel Prize.