Why did Jay's feet change into Yuki's?

There exists an unassuming house in a quaint neighborhood, owned by Yuki, a 48-year-old woman known for her rich Japanese heritage laced with a hint of enigma. Fiercely protective of her abode, she maintained a strict 'no shoes" rule, irrespective of the visitor. She often showed off her private collection of traditional Geisha attire, which fascinated the neighborhood, including 16-year-old Jay. One sunny afternoon, the usually reclusive Yuki had to break her pattern and run some errands, thus turning to Jay to house-sit. As she left, Jay bowed in respect, following their goodbye ritual obsessively. Once Yuki left, Jay found himself contemplating the house rules. An unusually rebellious musing had him scampering around the house searching for his shoes, his heart pounding, fear and excitement knitting an adrenaline-filled pattern in his gut. He discovered them conspicuously placed amongst Yuki's traditional clothes, Geisha gear, and the meticulously lined Japanese shoes. The audacious teenager made a calculated move, surreptitiously attempting to put on his shoes. But fate had another story in mind. His foot inadvertently slid into Yuki's delicate flip-flops. A colossal pain surged through him as his feet gracefully aged, shrinking from 16-year-old Jay's muscular outline to 48-year-old Yuki's dainty ones, holding a perfect French pedicure. Jay plateaued on fear's summit. He watched, aghast, as his body metamorphosed. The once exuberant youth found his clothes transmuting into Yuki's elegant dress as if slyly replaced by an invisible seamstress. His face soon embraced the Geisha makeup, a fan magically forming in his slightly trembling hand. Jay's transformation was complete. Looking at himself in the mirror triggered a wave of melancholy. His once youthful countenance replaced by a face, though reminiscent of Yuki's cherubic charm, bore the inescapable stamp of time. As his memories warped, a terrifying calmness took over him. Jay's existence started blurring, yielding its space for the emergence of a new entity – Yuki. The transformed Yuki looked at herself in the mirror, traces of bewilderment knitting her forehead. Unable to recollect her morning errands, she found herself confused within the comfort of her household. She left the bedroom, her beautifully adorned feet making a soft sound against the hardwood floor, tofind out if her young neighbor Jay was still around, unaware of the strange alignment of fate.