Between 1318 and 1319 when the miyashogun (shogun from the Imperial Court) Imperial Prince Morikuni was the Seii taishogun (literally, 'the great general who subdues the barbarians'), substituting the aged Nichiro, Nichiin refuted all of the priests representing other sects before Takatoki HOJO, the regent and Tokuso (the patrimonial head of the main branch of the Hojo clan) of the Kamakura bakufu (so called the Kamakura denchu mondo (the Questions and Answers Session at the Shogunate Residence in Kamakura) (Nichiin's pupil Nichijo took the minutes of that session.
1318年（文保2年）～1319年（元応元年）に日印は高齢の日朗に代わり、征夷大将軍が宮将軍の守邦親王の世の鎌倉幕府の執権・得宗の北条高時の前で他の諸宗の僧を論破（いわゆる鎌倉殿中問答）（弟子の日静が書き留める。）し、日蓮門下の宗門の危機を救う。