Movie
Description
Rin Natsuki attends L'École des Cinq Lumières as a second-year student and is Nozomi Yumehara's childhood friend. She balances tomboyish energy with feminine interests, channeling creativity into accessory design for Natts House. Her straightforward, grounded personality makes her a nurturing presence for Nozomi and her siblings, Ai and Yu, enduring their teasing with deep affection. Occasional hot-headedness sparks friction with reserved peers like Karen Minazuki, though they forge effective teamwork. Childhood experiences fuel Rin's fear of supernatural events and persistent dread of losing loved ones.

When Rin witnesses Nozomi—as Cure Dream—battling an enemy, her protective instinct compels her to accept the red butterfly's power. She transforms into Cure Rouge, the fiery Pretty Cure of Passion. This metamorphosis ignites her hair into bright red flames, accented by a magenta swallowtail butterfly hair clip and red butterfly earrings. Her battle attire blends red and pale cream with butterfly motifs, coral boots, and a swallowtail bow clasped by a green gem brooch. Wielding fire-based abilities like Fire Strike, she declares herself "The red flame of passion, Cure Rouge!"

In the movie *Okashi no Kuni no Happy Birthday*, Rin joins Nozomi's birthday celebration, disrupted by Princess Chocola's arrival from the Dessert Kingdom. After aiding Chocola, Rin and her friends visit the sweets-constructed realm. There, they confront villains Mushiban, Dry, and Bitter. Separated from the group, Rin and Karen face Dry, who traps them in refrigeration to transform them into frozen desserts. Temporarily turned to ice cream, they shatter free upon sensing Cure Dream's distress, reigniting their resolve. Rin and Karen defeat Dry using combined Fire Strike and Sapphire Arrow attacks.

Relationships anchor Rin's growth: her foundational bond with Nozomi drives her decision to become a Pretty Cure, while clashes with Karen evolve into battle-tested respect. She briefly develops romantic feelings for Momoi Kyosuke, later exposed as the fairy Mucardia in disguise, severing ties upon uncovering his deceit.

As an adult, Rin sports shoulder-length auburn hair and refined fashion—ruffled blouses, skirts, gold bracelets, and red earrings—reflecting her ongoing design career. Her name "Natsuki" fuses "summer" (natsu) for her fire powers and "tree" (ki), while "Rin" (in hiragana) subtly hints at dignity through potential kanji readings. Her alias "Cure Rouge" draws from French for "red," mirroring her color theme.