Keiichi Kato (加藤 圭一 Katō Keiichi) is a fourth-year student at Johoku Medical School (城北医科大学 Jōhoku Ika Daigaku) and the cousin of Megumi Kato.
Keiichi has short, spiky and quite straight brown hair that reaches to his ears and blue-sea eyes.
Keiichi's personality has not been revealed so much, but what is known it that he seems to be soft spoken, polite and collected.
Megumi is Keiichi's cousin and he calls her Megumi-chan.
- The name Keiichi means means "noble" (圭) (kei) and "one" (一) (ichi).
- Keiichi's surname Kato means "add, increase" (加) (ka) and "wisteria" (藤) (tou).
- Kato is an alternate transcription of Katou.