Being orphaned at very young age, Tosai had unhappy upbringing but, during the visit of Jikuan Join, the naturalized priest from Qing, to Kofuku-ji Temple in Nagasaki (Nagasaki City), Jikuan Join took a kindly interest in Tosai whereby Tosai became his disciple.
幼くして孤児となり不遇な生い立ちでは会ったが、清の帰化僧竺庵浄印が長崎の興福寺(長崎市)に来たとき、竺庵に目をかけられこれに入門。