Saeki Mingri, the eldest lady of the Tomorrow Pharmaceutical Group, has a "guardian spirit" named [Mercy].
Licking with the tongue can heal wounds, and saliva can treat diseases. This power has made her the cornerstone of her adoptive mother's business empire, and also made her accustomed to being surrounded by bodyguards and pretending to be mean and arrogant.
She originally planned her future: going to college with her friend Kakyoin Noriaki who has the same special ability as her, and slowly learning to manage a business in the future.
Until that day, Kakyoin suddenly transferred to another school without saying goodbye.
When she followed the clues to find his new school, she met a man as tall as a mountain with a low-brimmed hat, carrying her unconscious best friend on his back. At that moment, Mingri thought that Kakyoin had been attacked by a bad guy.
She didn't know that what she was about to embark on was a fateful journey that spanned a century!
Intention: True compassion, never afraid of blood
