In Tagi District in 1079, he fought in the big battle against MINAMOTO no Shigemune, who was also based in Mino Province, therefore the both parties were summoned to Imperial Court later, and Kunifusa was confined in Yuniwa for the duel.
承暦3年（1079年）には、多芸郡において同じく美濃国内に地盤を有する源重宗と大規模な合戦を演じたことから、後に両者とも朝廷に召され国房は私闘の罪により弓庭に拘じられた。