Hina Hikawa, the younger twin of Sayo Hikawa, balances her role as Pastel*Palettes’ guitarist with first-year studies at Keiho Women’s University. Initially joining the band on a whim via audition, her casual involvement deepened through bonds with members like Aya, transforming her commitment. A former Haneoka Girls’ High student council president, she single-handedly sustained its Astronomy Club—dubbed "The Weirdos Club"—hinting at her affinity for the unconventional.

A prodigy with flawless recall, Hina masters skills instantly, her boredom threshold low and curiosity insatiable. Her cheerful, unfiltered demeanor masks occasional social missteps, her speech peppered with playful ideophones like "zappin’♪." Hobbies span crafting aroma oils, devouring occult magazines such as *Supernatural Encounters*, and volleyball, reflecting her eclectic tastes.

Twin dynamics define her relationship with Sayo: Hina’s emulation of Sayo’s guitar pursuits inadvertently strained their bond, perceived as rivalry rather than a bridge. Yet persistent efforts to connect fostered mutual growth, easing past tensions. Hina openly celebrates their twin identity—embodying "sun" (日) to Sayo’s "night" (夜)—her unwavering support evident in covert attendance at Sayo’s Roselia performances, disguised to avoid unsettling her sister.

Fascinated by cryptids and extraterrestrial lore after *The Mole Person☆Transport Mission!*, she pairs supernatural curiosity with academic prowess, excelling in English and topping classes despite puzzling over map symbols. Her light teal braids with yellow bows and tomboyish attire contrast Pastel*Palettes’ frilly aesthetic, mirroring her sunlit spontaneity against Sayo’s reserved depth. Evolving emotional nuance surfaces in metaphorical gestures of care, underscoring her dedication to bandmates and family alike.