The practical difference is simple: NH35A drives a date display. NH38A is built for a dial without one.
The shared foundation
Both movements belong to the same established automatic-movement family. They wind from wrist movement, can also be wound by hand and allow the seconds hand to stop while setting the time.
Their shared architecture makes the choice less about prestige and more about the dial you prefer. Kuro uses the movement that belongs with each dial configuration.
Choose the display, not the acronym
The NH35A version powers Kuro’s date window at 4:30. The NH38A version removes the date mechanism from the display and supports a cleaner dial. Neither layout is universally better.
A date is useful if you check it often. A no-date dial is quieter and never needs correction after a short month. Pick the version that fits how you use a watch.
Daily behaviour
The stated power reserve is about 41 hours and the operating frequency is 21,600 vibrations per hour. Mechanical accuracy varies with position, temperature, state of wind and the individual movement. A mechanical watch is a small machine, not a quartz reference clock.