According to the popular theory, Kawaguchi got on very well with Saigo from the first time they met; and everyday Kawaguchi visited Saigo's cell of the prison of Wadomari which was 3.4 kilometers away from Nishihara and discussed current issues and talked about learning, and he came to teach calligraphy and poetry to Saigo.
通説によれば、西郷とは初対面から大いに意気投合し、西原から1里弱(3.4km)離れた和泊の西郷の座敷牢まで毎日のように通っては、時世を論じ学問を語り、書や詩作を教えるようになった。