Both are narrative and simple in terms of animation, also, while Nihon no Mukashi Banashi tells old traditional folklore tales, Yami Shibai tells scary modern folklore and urban legends. If you liked Nihon no Mukashi Banashi you might want to try out in addition scary tales that Yami Shibai offers.
If you like Nihon no Mukashi Banashi you might like Kobu-tori, a 10 minute short movie from 1929 about villager with a lump and group of tengu, which is one of the folktales in Mukashi Banashi, if you like folktales you might want to check this old version too.
If you want to learn more about Japanese culture and traditions, those shows are for you. Nihon no Mukashi Banashi will tell you the folktales through short stories that everybody can enjoy without any knowledge of Japan, and those OVA of Rockman/Megaman make you discover the Japanese lifestyle, their customs and festivals. They're also both accessible to children as well as adults.
Both are about japanese literature/culture/history , and their main aim is to teach japanese magnificient literature to the audience, instead of telling a main story just like a normal anime. However, both shows are also very entertaining and easy to watch.