Itsuki Myōdōin, alias Cure Sunshine, navigates a complex interplay of identity and duty as a central protagonist. A second-year student council president at Myōdō Academy, she adopts a princely, masculine persona to preserve her family’s dojo legacy in place of her ailing brother, Satsuki. This facade masks her private affection for dolls and dresses, creating a tension between societal obligations and personal authenticity. Her self-discovery unfolds when classmates Tsubomi and Erika invite her into the fashion club, where she designs feminine attire, gradually embracing her true tastes.

Her transformation into Cure Sunshine ignites in episode 22 after saving fairy companion Potpourri and defending Satsuki’s Heart Flower from a Desertrian. Wielding solar-themed abilities tied to sunflowers, her attacks—Sunflower Aegis, Sunshine Flash, and Gold Forte Burst—embody nurturing light and banishing shadows. The Super Cure Sunshine form amplifies her power with elongated hair, a heart tiara, and rainbow wings, while the *Heartcatch PreCure!* movie introduces her cosmic Infinity Silhouette, merging with fellow Cures for universe-level strength.

Key bonds shape her journey: devotion to Satsuki fuels her protective resolve, while friendships with Tsubomi and Erika empower her femininity. A once-distant rapport with mentor Yuri evolves into mutual trust. Her internal strife peaks in episode 37, reconciling her past as the family’s stoic heir with her present self, uniting both identities into a cohesive whole.

Trained in martial arts from age four or five—a detail reflecting her family’s disciplined ethos—Itsuki’s name, blending “bright,” “magnificent,” and “timber trees,” mirrors her narrative themes of radiant growth. Her arc culminates in harmonizing duty with self-expression, inspiring others through unyielding compassion and resilience.