>>1484566Assuming "unify" meant that Yamagata Shinkansen extends all the way to join the Akita Shinkansen at Omagari (hence getting to Akita through Ou Main Line like the old Tsubasa did), the major hurdle is whether it'll be financially viable to convert the train tracks to standard gauge and upgrade some sections if needed so it could run at 130 km/h for the 100-ish km between Shinjo and Omagari Stations. Although this does give JR East an out if the service between Omgari and Morioka gets interrupted by whatever reason it would give them an alternative to reduce disruptions.
