Nichiro was so old that he sent his pupil, Nichiin to have a debate between Daimoku sect and every other sect of Japanese Buddhism during the period from January 30, 1319 to November 5, 1319 (Kamakura denchu mondo Dialogue).
日朗は高齢ゆえに弟子日印を出し、文保2年（1318年）12月30日から翌元応元年（1319年）9月15日にかけて題目宗と日本仏教全宗派と法論を戦わせた（鎌倉殿中問答）。