Kashou Minaduki descends from a long lineage of traditional Japanese confectioners. Raised under strict expectations to inherit the family's wagashi business, his childhood lacked typical social experiences or hobbies due to intense focus on mastering family recipes. This changed when he ran away to study abroad in France. Visiting a patisserie there revealed his true calling; seeing patrons smile while eating Western-style cakes inspired him to become a patissier. He apprenticed at that shop, naming his future shop "La Soleil" in honor of his mentor. His career choice created estrangement from his disapproving father, leading Kashou to leave home secretly after returning to Japan.

Six months before opening La Soleil, Kashou and his sister Shigure discovered orphaned catgirls Chocola and Vanilla in the rain. He took them in, and their gradual adaptation to the Minaduki household solidified his resolve to pursue patisserie independently. When moving to start La Soleil, he found Chocola and Vanilla had stowed away in his boxes. Despite initial efforts to return them, their persistence convinced him to let them stay. He trained them as shop assistants, navigating legal requirements like their Independent Action Permits, symbolized by bells. This marked the beginning of their collaborative life running the patisserie.

Kashou exhibits a blend of independence and nurturing responsibility. He manages all aspects of La Soleil, from baking to supply procurement, driven by a desire to bring joy through his creations. Though socially reserved and occasionally oblivious to romantic cues, he consistently supports the catgirls' emotional growth, helping them overcome insecurities or achieve goals like earning their bells. His patience extends to mentoring; he guides Coconut through her self-doubt in Vol. 2, leading her to affectionately call him "Onii-chan." However, his dense nature complicates relationships, as he struggles to recognize romantic advances from the catgirls or his sister Shigure.

His development intensifies in Vol. 4, centered on reconciling his patisserie philosophy with familial expectations. Flashbacks reveal his father's dismissal of Western confections, fueling Kashou's need for validation. When his father effortlessly replicates his mentor's whipped cream—a technique Kashou had struggled to perfect—he confronts his unresolved need for paternal approval. This catalyzes a deeper understanding of his motivations: baking not just for others' smiles but to honor his own values. The arc culminates in tentative reconciliation with his father, who begins acknowledging his son's skills.

Kashou's relationships with the catgirls evolve from caretaker to mutual emotional reliance. Initially viewing Chocola and Vanilla as daughters, he gradually acknowledges romantic tension, particularly during quiet moments like their park bench conversations. By Vol. 3, he accepts polyamorous bonds with all six catgirls, balancing guilt over shifting dynamics with genuine affection. His role expands in the anime when approving Chocola's adoption of a stray kitten, Cacao, further emphasizing his compassionate leadership within their unconventional family.

Technologically pragmatic, he relies on Shigure for La Soleil's social media management, focusing instead on recipe innovation and daily operations. His attire typically includes practical chef uniforms while working and casual neko-themed shirts otherwise, reflecting his dual identities as baker and caregiver.