Hazuki Yazakura is the adopted elder sister of Chitose Hitotose and Minazuki Rokumatsuri, sharing a close-knit sibling bond despite lacking blood ties. A celebrated pop idol dominating Japan’s music scene, she captivates nationwide audiences with her charismatic performances and vocal talent, her demanding tour schedule frequently keeping her on the road. Though often absent, she remains an integral part of her household’s daily life, weaving herself into its rhythms during brief respites from her career.

Her signature trait is her mastery of "Okadu," a fictional martial art centered on rapid food consumption. The discipline follows an inverted hierarchy, with level ten as its entry point and level one representing near-impossible mastery. As the titled Obakyu and a sub-instructor of Okadu, she has achieved its pinnacle, level two. The style’s distinctive costume—hinted in a flashback with Chitose—draws playful visual inspiration from the vintage character Obaky no Q-taro, blending whimsy with nostalgic flair.

Within her family, Hazuki balances affectionate mentorship with spirited camaraderie. Her sporadic presence fuels lighthearted rivalries, notably clashing in eating contests against figures like Satsuki Gokajo to showcase her unmatched gastronomic speed. Her bond with Chitose remains firmly platonic, anchored in their shared adoptive history and mutual respect. The narrative consistently frames her through three core pillars: her idol prominence, Okadu expertise, and role as a supportive yet intermittently present sibling, with no expansion on personal growth or backstory beyond her adoption and profession.