Shizue and Yui Kori

Shizue and Yui Kori are secondary antagonists in Sugimoto Gynecology Clinic ~Nurse Reform Program~.

Appearance
Shizue and Yui are non-identical twins; Shizue is light-skinned and blonde, while Yui is dark-skinned with platinum hair. Both of them wear an identical uniform: white, pink-accented zip-up crop tops with a pink heart-and-cross sigil adorned with devil horns across the left breast, nurse's hats with the same logo, mini-skirts in the same style held up with pink belts, and thigh-high heeled white boots. The two of them also wear chokers and have a tattoo with "devil nurse" emblazoned on it on their left shoulders.

Traits
Shizue and Yui appear to have a sadistic level of dedication to their job, inflicting severe amounts of discomfort on Kenji Kataoka and having sex with him against his will for the purposes of maximizing his treatments. They also appear to not have much love for Chiha Rokuhato, taking great pleasure in causing her pain by having sex with Kenji. This may also be because of Chiha's disregard for proper on-the-job conduct.

in Sugimoto Gynecology Clinic
The twins are secondary antagonists in Sugimoto Gynecology Clinic, as nurses sent from the "special facility" to aid in administering a special treatment to Kenji Kataoka. They first appear when Shoko Sugimoto confronts Chiha about her infidelity on the job, ordering Shizue and Yui to give Kenji a special sort of treatment while Chiha undergoes a correction program, which they gossip about while taking Kenji to the treatment room. There, they sit him in a gynecology chair and begin treatment, nearly bringing him to climax. However, just as he reaches it, Shizue inserts the Ever Sundome into his penis, which works as an ejaculation restrictor, preventing him from ejaculating. This causes Kenji's penis to swell as he is denied orgasm, causing a significant amount of discomfort, which Shizue and Yui ignore as they continue to use him for their own purposes through the course of the treatment. Eventually, as Chiha is forced to watch while she is raped as part of the correction program, Shoko joins them in having sex with Kenji, finally allowing him to ejaculate as he and Shoko climax together.

Trivia

 * When UMEMARO first made mention of the twins, in his September 29, 2015 blog post, many fans considered that he may have been referring to another set of twins instead. Shizue and Yui do have similarities to the former pair, including their sadistic nature and dark pleasure taken in forced sex with men, as well as the fact that one twin (Yui and Kamira) is unusually dark-skinned, particularly compared to their respective twins (Shizue and Kurusu).