Since guilt-by-association system was taken in the Edo period, some mushuku were townspeople who had been disowned by his family because of his misconduct for fear of being involved in, and people who had been transported due to misdemeanor.
無宿には、江戸時代は連座の制度があったため、その累が及ぶことを恐れた親族から不行跡を理由に勘当された町人、軽罪を犯して追放刑を受けた者もいた。