According to "Kohakusaiki" (a diary and record on the history of the Sengoku period supposedly written by Masatake Komai), in 1521 when Shingen was born, Lady Oi retreated to Yogai-yama Mountain, while 15000 soldiers led by Masashige KUSHIMA under the order of Ujichika IMAGAWA of Suruga Province closed on Kofu, but were subsequently beat off by the Takeda army at Arakawahata (Kofu City).
『高白斎記』によれば信玄が誕生した大永元年（1521年）には駿河国今川氏親の命を受けた福島正成率いる1万5000人の軍勢が甲府に迫おり、大井夫人は要害山へ退いていたといわれ、武田方は荒川幡（甲府市）において今川方を撃退する。