Luigi began as a different color of Mario

A name with a Japanese echo

Luigi is written in Japanese as ルイージ and pronounced roughly “ru-ee-jee.” That sound sits close to ruiji (類似), a Japanese word meaning “similarity” or “resemblance.” The names are not identical, but the resemblance is enough to make Luigi’s name work as a small phonetic joke: Mario’s brother sounds, in Japanese, like someone defined by being similar.

That meaning fits the characters’ relationship, but it is an echo rather than a translation. Luigi remains an Italian-style personal name; Japanese speakers do not read it as the ordinary word for “similar.” The joke comes from hearing the two sounds side by side.

The pizzeria story—and the extra layer

Nintendo reportedly settled on the name after noticing a nearby pizzeria called “Ruigi.” If that account is right, the restaurant supplied the name’s starting point, while its resemblance to ruiji gave it an additional resonance for Japanese players.

That double fit is a neat piece of naming economy: one name can sound plausible as a character’s name and also quietly describe his role. Luigi is not merely another Mario; the sound of his name carries a hint of the resemblance that makes the pairing instantly legible.