Ryuu no Haisha (龍の歯医者, lit. "The Dragon Dentist") is a manga series by Outarou Maijou with illustrations by Youko. It has an 8-minute-long original net animation that was released as the first part of Hideaki Anno's Animator Expo. A two-part anime television special adaptation was aired in February 2017.
The story takes place in Dragon Country. Nonoko is a newly appointed dentist and her mission is to protect the dragon, the guardian of the country, from tooth-cavity bacteria.
One day, amid increasingly fierce battles with the neighboring country, Nonoko finds on the dragon's tooth an unconscious boy soldier from the enemy country. His name is Bell, and he has been resurrected from inside the tooth by the dragon—a supernatural phenomenon that legend says occurs before a major disaster. As Nonoko and Bell go through a series of fierce battles, they eventually learn to accept their fate.