A new Japonicum that has great potential . The least of which it adds another VERY hardy cultivar to your list of super safe JMs for colder climates. My one year experience with this tree is very very positive it is super cool and a keeper . the photo was in early fall the red is very nice in late fall and it hold a nice long time .. This should be on your list.
Whether this is a japonicum or shirasawanum has not yet been decided. Is this Ruby or Ruby Red. Time will tell.
Winter Hardiness: Zone 5 - Down to -20°
Summer Hardiness: Tree will be planted in full sun