It was told that the lord of Kamachi in Kamachi-jo Castle was from the family of FUJIWARA no Suminori, but Yanagawa-jo Castle did not exist at that time, and it was at Kamachi-jo Castle that TACHIBANA no Kimiyori and his son TACHIBANA no Toshimichi made a counterattack.
そこから蒲池城に拠る蒲池の領主は藤原純乗の一族と伝えられているが、当時は柳川城はまだなく、橘公頼が子の橘敏通と共に藤原純乗を迎え撃ったのは蒲池城である。