Nobunaga TAKEDA (the second son of Nobumitsu TAKEDA), who had became a vassal of the Koga-kubo, Shigeuji ASHIKAGA, invaded Kazusa Province as ordered by Shigeuji, and embezzled the territory of the Kanto Kanrei Uesugi clan in the province, based on which event the Mariya clan emerged and became a warlord.
この真理谷氏は武田信満の次男・武田信長が古河公方であった足利成氏の家臣となって、その命令を受けて上総に攻め込み、同地で関東管領である上杉氏の所領を横領するなどして戦国大名化した一族である。