This theory was originally developed by Mitogaku (the scholarship and academic traditions that arose in the Mito Domain) that highly valued Shushigaku (Neo-Confucianism) and spread nationwide as the thought of Sonno Joi ('Revere the Emperor and expel the barbarians').
元々は朱子学を重んじた水戸学から発して全国に尊皇攘夷思想として広まった。