Riko had been enjoying her solitary life until her parents insisted she take in her uncle Rikuto. Once a charismatic and handsome man, Rikuto now found himself in a humiliating situation, pleading for Riko's forgiveness with panties on his head. Despite his disgraceful state, Riko couldn't deny the strange attraction she felt towards him and decided to let him stay, but with a twist—as her personal "pet."

Intrigued and somewhat shy, Riko often retreated into her own world of fantasies. During her period, she started to explore this new dynamic, issuing intimate commands to Rikuto. Eager to please, her "pet" followed her instructions, touching and pleasuring her exactly as she desired, fulfilling her every whim.