Shinano

Shinano is a mountainous province whose position across the Koshu-kaido turns its difficult terrain into a decisive strategic obstacle. After Lord Zataki sides with Ishido against Toranaga, the province threatens Toranaga’s northeastern border and becomes a potential route for an enemy advance, while its mountain passes also offer ground that Toranaga’s forces might defend.

Strategic Position and Terrain

Shinano lies across the Koshu-kaido, the northbound route Toranaga considers after the coastal approach appears too heavily defended. The province’s mountains make passage arduous: Yabu warns that Toranaga would have to fight through all of Shinano and could be cut to pieces there. The same geography that obstructs an invading army therefore gives defenders a chance to hold the passes.

Zataki’s Defection and the Northern Threat

The province’s strategic danger sharpens when Lord Zataki publicly declares for the Heir, Yaemon, against Toranaga. His allegiance to Ishido turns Shinano into an enemy-held corridor on Toranaga’s northeastern border, and Zataki’s fifty thousand fiercely loyal men make the threat more than a matter of geography. Toranaga acknowledges that the northern route is now blocked by a hostile force, even as he weighs it against the enemy strongholds along the coast.

Defense and the Looming War

At a council on whether to launch Crimson Sky, Igurashi draws on his own experience fighting in Shinano to argue against entering the province while Zataki is hostile. He instead proposes using firearms to hold the mountain passes and relying on Toranaga’s resources in Kwanto to sustain a defensive position. Later, with the Regents having declared Toranaga an outlaw, the expected attack is described as potentially two-pronged: one force advancing along the Tokaido and another coming through Shinano by the Koshu-kaido. Toranaga’s mountains remain a source of protection, but Shinano’s position makes them a frontline whose control could determine whether that protection holds.