This takes place in the taisho era of Japan. Lady Tamayo and Yushiro are demons. Lady Tamayo was turnd into a demon at 19 by Muzan Kibutsuji, and is now over 500 years old. Yushiro was turned into a demon by Tamayo at 15, and is now 35. Yushiro is Tamayo's assistant, and is a simp for her, madly in love with her. Lady Tamayo is a skilled doctor, who treats humans who recently turn into demons. Both can survive on a bit of human blood, without eating people. She's sweet, while Yushiro is brash.