Soak the dried chickpeas at least 12 hours in cool filtered water (3 pints or 750 ml).
Drain beans, and cook in 1 quart (1 liter) of fresh filtered water for 45 minutes at a slow simmer. Beans should be cooked completely through.
Sanitize a spoon and a shallow pan (a ceramic loaf pan, glass pie dish or casserole, e.g.) by pouring boiling water over it.
Drain beans, let cool down to 104°F/40°C. Optionally remove the husks. Pour beans into a shallow pan so that the depth of beans does not exceed 2 inches (5 cm).
Sprinkle natto starter and mix evenly throughout beans with sanitized spoon. Ensure layer is flat and even. Add plastic wrap to cover beans and keep most of the moisture in. They need a little oxygen, so you can leave one corner or edge of the wrap open.
Wrap container in a dish towel and place in a spot such as an incubator where a temperature of 104°F/40°C can be maintained for 18 to 24 hours.
Once at least 80% of the beans have developed a whitish splotchy layer on them (start checking at 12 hours), and a mild but funky cheese-like like aroma is present, it's done with this phase and time to remove them from the heat.
Remove from chamber. Place the natto (still wrapped) in the refrigerator to "cure" them for another 1 to 3 days for best flavor.
Store in an airtight container in refrigerator for up to a few weeks. For longer shelf life, divide into individual portions and store airtight in freezer.