In the first position "Kissing the Cow," Rin Ninomiya instructs her student (her student is herself a former porn star) to masturbate with her vagina and then literally until she reaches a climax. So how much do you know about how a girl climaxes? Do you know that women tend to have different levels of orgasm? Do you know that each girl climaxes in different ways? This is exactly why Rin Ninomiya, one of the best female masturbators today, focuses on clitoral stimulation when making love to her partner..