|Oh dear... That's not very good.|
Sei Doi is a bit character in the film Perfect Blue.
Sei Doi is a very rude young man. At CHAM!'s concert, both he and his gang act drunk and then threw beer cans at the singers. Uchida, who is a security officer, tries to stop them, but he is then punched in the face by Sei Doi. The gang continues to beat Uchida, until the audience orders them to leave and they throw trash at them. Mima orders them to stop and Sei Doi and his gang decide to leave, leaving a bloody Uchida behind.
Sei Doi is the leader of a gang with at least three other followers.