Why is the name 五右衛門 read as ごえもん?
How can the three kanji 五右衛 be read with only two syllables?
Originally, these kanji were thought to be pronounced as:
右衛門: u we mon
But since Japanese u and consonant w have little difference, the actual pronunciation was like:
右衛門: wwe~we mon
Later, undergone the phonological change that merged wi, we, wo into i, e, o:
右衛門: e mon
So the truth is 右 and 衛 share a single syllable, but the fact has been obscured by the sound change.