It is said thatthe rice omelet was invented for a regular patron with a sensitive stomach who always ordered an omelet and plain rice and, in sympathy for the patron eating the same thing all the time, the restaurant owner one day cooked up a rice omelet for a change.
白飯とオムレツを別々に頼んでいた胃が弱い常連客を見て「いつも同じものでは可哀そうだから」という思いから生まれたとされる。