Neko manma translates literally as "cat rice", which means cat food. It usually consists of a bowl of rice with various toppings, which can range from bonito flakes to fish bones, miso soup, or mayonnaise. The difference seems to depend on where in Japan you are from.
It is said that neko manma was originally intended as cat food, and made from leftovers. Ironically, most neko manma combinations call for oils and condiments that aren't suitable for cats' diets.
Felines often appear in Japanese mythology, and they are viewed with respect and fear. The maneki neko, or beckoning cat, will bring fortune, whereas the bakeneko, the vampire cat, was an evil spirit.
In the hit comic book series Shinya Shokudo, about a late-night diner in Tokyo's red-light district, a character begins meowing after eating a bowl of neko manma. She returns to the restaurant after her death in the form of a cat.
Manma is baby talk for rice, and some say it's called that because it reminds people of the food they had as children. Others say it's because it was served to cute kittens.
In and around Tokyo, neko manma generally consists of rice topped with bonito flakes and soy sauce. Butter is produced up north in Hokkaido, so that is added there. Others add miso soup, hot pot soup, raw egg, or whatever is handy.