Zach,

There are always many variables even from year to year in the same spot. Why not see which does best for you by planting both?

Just finished the google search on "Tohya"; boy is Botanical Interests hyping this, same entry everywhere word-for-word... but I eventually found a favorable reference to it in a Canadian field trial, so it should do well for you. I will have to add this one to my soy trials for next year.

Most of the other popular edamame varieties ("Butterbean", "Shirofumi", "Shironomai", "Sayamusume") are Maturity Group I; "Envy" is a little faster in Group 0, and "Agate" faster still in Group 00. I have grown all of these in central Wisconsin, so you should have no trouble. Hope this helps.