Kaya Kikuma, nicknamed Kayatan, stands as the oldest member of her idol group at age 18. Her image color is green, paired with a crocodile motif. She sports slightly wavy, mid-back-length dirty blonde hair and wide green eyes. As the senior member, she consistently prioritizes others, demonstrating generosity and support toward friends and family, though fellow members note her occasionally aggressive and blunt demeanor.

Originally from Kesennuma, Kaya relocated to her aunt’s care after her parents' death in childhood. She later moved to Sendai, taking multiple part-time jobs following the disappearance of the fishing vessel "Shotomaru" three years before the series—a tragedy that claimed her childhood friend. She joined the idol group on impulse, intending to depart if it grew dull, but ultimately embraced full commitment. Within the group, she operates as the sub-leader, supporting the de facto leader.

In the spin-off "Wake Up, Girl ZOO!," she embodies a crocodile mascot, aligning with her animal motif. This series reimagines the group as mascots in Sendai’s struggling zoo, retaining Kaya’s core traits of supportiveness and bluntness. One episode spotlights her in a pro-wrestling segment where members comically critique each other’s flaws.

Her background reflects profound loss and instability, shifting from transient work to purpose within the group. This evolution highlights her transition from fleeting commitments to steadfast dedication, underscoring loyalty and perseverance. The recurring crocodile motif symbolizes her resilience and adaptability across both main narratives and comedic spin-offs.