This page is of questionable balance. Reason: Super heavy armor with a dex bonus? the most extreme armor is the dwarven plate with +11 AC and no dex modifier, why would this have +4 ac +2 dex and cost less than half?
If you look at an image of a Do-maru it is a japanese scale armor with a plateskirt. This would allow extremely good AC due to blades grazing off the scales, and a high dex because every part of the armor of flexible.
Do-maru doesn't give much more protection than usual lamellar armor and it wasn't very flexible. That's why late Japanise noblemen prefered spainish-made plate cuirasses. Try to find and read some historical sourses before making such in-balanced items. I will suggest to change it's armor bonus to +7 and dex bonus will be the same. So it will be very good armor still fit to balance and historical authenticity.
You can help D&D Wiki by better balancing the mechanics of this page. When the mechanics have been changed so that this template is no longer applicable please remove this template. If you do not understand balance please leave comments on this page's talk page before making any edits. Edit this Page | All pages needing balance