It is thought, though not known for sure, that Arai Castle was built sometime during the Nanboku Period or Muromachi Period when the Ogasawara Clan were governors of Shinano. A branch of the Ogasawara called the Shimadate (or Shimadachi) ruled Araijō. The Shimadate were moved to Fukashijō (which would later become Matsumotojō) by the Ogasawara in 1523 but Shimadate Sadatomo stayed on as castellan at Araijō. Araijō was conquered and destroyed by Takeda Shingen in 1550.
The only ruin remaining at Arai Castle is a pokey bit of earthen embankment which now has a hokora (祠) on top. Araijō is also known as Shimizugajō (清水ヶ城) and there is a monument next to the shrine to a jūdōka called Shimizu, so I don't know if there's some connection there. A grand old house next to the castle ruin is also tenanted by the / a Shimizu family.
|English Name||Arai Castle|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Access||Shinano-Arai Station on the Kamikouchi Line; 2 minute walk|
|Visitor Information||24/7 free; private property|
|Time Required||10 minutes|
|Location||Matsumoto, Nagano Prefecture|
|Coordinates||36° 13' 51.60" N, 137° 57' 1.22" E|
|Added to Jcastle||2020|
|Admin Year Visited||Viewer Contributed|