After the opening of the port, the theory of Joi was related to the Sonno ron (theory of 'Revere the Emperor'), which was becoming prevalent due to the development of kokugaku (the study of Japanese literature and culture) and was transformed into Sonno joi ron (the theory of Sonno joi); the Sonno ron believed that Japan was the country of god and became origin of the thought of nationalism, and was supported by patriots of various domains and kugyo (court nobles).
開港以後は、国学(学問)の発展によって強化されつつあった日本は神国であるというナショナリズムの発想である尊皇論と結びつき、尊皇攘夷論となって諸藩の志士や公卿によって支持された。