Home to the Koshibami Clan, Koshibamijō was caught between two feuding giants. The lord of the castle, Koshibami Miyauchi, capitulated to Takeda Shingen, but planned to betray him and join up with Uesugi Kenshin, and so Shingen ordered his death. Hagiwara Yaemon and Kosaka Danjō, along with a few dozen of their mounted troops, journeyed to Koshibamijō and lured out Lord Koshibami by offering to gift him horses. He was then bundled off to Zenkōji where he was executed. And they say not to look a gift horse in the mouth...
Koshibamijō is a small castle ruin. There is a shukuruwa (main bailey) with a koshikuruwa (sub-bailey) half surrounding it below. A couple of pocket baileys strike off down the ridge from here. Dorui (earthen ramparts) surrounds parts of the shukuruwa, at the rear of which there is a karabori (dry moat) system, yokobori (lateral moat) or horikiri (trench) terminating in tatebori (climbing moats) at each end. Then there is a modern road, which may have been built over a double trench system. Beyond here is an empty field at slightly higher elevation which may have been a secondary bailey of the old castle.
|English Name||Koshibami Castle|
|Year Founded||Sengoku Period|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Artifacts||Kuruwa, Horikiri, Tatebori, Dorui, Koshikuruwa|
|Access||Nagano Station; 20 minute walk|
|Visitor Information||Free; 24/7; Mountain|
|Time Required||30 minutes|
|Location||Nagano, Nagano Prefecture|
|Coordinates||36° 38' 48.12" N, 138° 10' 29.60" E|
|Added to Jcastle||2021|
|Admin Year Visited||Viewer Contributed|
|Friends of JCastle|