Nyakumi has short, dark hair tied up in two pigtails, with large brown eyes. In Nyakumi, she wears a gym uniform consisting of a white ringer tee with a red collar and sleeves, as well as blue shorts with white stripes. In OMEGA, she is naked for much of her scene, only wearing the University of Yomei uniform at the very end and in promotional artwork.
Nyakumi was the first Nyakumi.net girl to feature any true sort of characterization, which stays consistent between her two appearances. She is shy and timid, clinging to her boyfriend in Nyakumi and staying nervously silent in the presence of another man in OMEGA, but this hides an insatiable sexual appetite that seemed to develop in the wake of Nyakumi.
Nyakumi is the titular character of Nyakumi.net 3D’s fourth release. The video begins with her waiting for her boyfriend in the gym’s storage closet. When he arrives, she proceeds to give him a blowjob and titjob, which escalates into sex. However, during this, two other men enter the room, one taking her anus, the other taking her mouth. She is raped by these two men until they climax along with her boyfriend, who subsequently leaves with Sasa, abandoning Nyakumi to be raped by the other men.
Nyakumi has a single scene in OMEGA, in which Ohara discovers her having sex with Shiori Tamiya in an otherwise empty classroom. Shiori notices him, and admonishes him for spying on them. She brings him into the room, and demands that he pleasure Nyakumi, who has become incredibly horny just from seeing him. He proceeds to have sex with the both of them, immediately after which Kayo Shinozaki appears, inquiring as to what Ohara has been doing, walking in to see the three of them, fully clothed, lulling about the room.
Nyakumi is the first character in the entire Nyakumi.net 3D canon to be shown in a proper lesbian scene, with her partner Shiori.
Nyakumi shares her voice actress with Ai Koyanagi and Miyuki Kageyama.
She was a virgin before having sex with Togo, as evidenced by her line “Kon’na no hajimete!”, which translates as “This is my first time!”.