One thing that immediately caught our eye while watching this early version of Hina was the wide leg stance and feet that are slightly toed out. This is a very different, and much more stable, approach than the rectilinear approach used by most robot kit manufacturers and hobbyists in the past. Even the 3rd generation Kondo humanoid robot kit, the KHR-3HV, is basically rectilinear and suffers the inherent instability issues that come with right angle designs. Biological creatures, like you and I for example, almost never come with right angles or square corners.
Try putting your heels, back, and head flat against a wall to get them all in a straight line, then try walking forward holding that posture without falling down. You’ll quickly understand why most of the 1st and 2nd generation humanoids have trouble walking, or even maintaining their balance while standing still. It’s something that Hina’s creator seems to have understood, either logically or intuitively.