Congratulations.
I second something close or similiar to Sango Kaku ... a red bark cultivar, most likely of the Aureum group.
Seems that this one caught a bight of sun already, Sango Kaku has quite lime green tones in summer, changing to pale yellow and than reddish like yours. Well, that's what my does.
I guess, you will find out in giving this tree a good home.