On Okinawa, the family name is typically pronounced ‘Higaonna’ while on the Japanese mainland it is usually pronounced ‘Higashionna’. But you may be surprised that the kanji that comprise the name can be read multiple ways (albeit rarely). Let’s take a look at some (1):
とうおんな 【東恩納】 Touonna
Personally, being a student of Touon-ryu (東恩流) I always wondered why its founder, Kyoda Juhatsu, never called the style ‘Higaonna-ryu’ or, sticking to the on-yomi (Chinese reading), why not ‘Touonna-ryu’? If I was a to make an uneducated guess, I would think it simply had to do with the naming convention of pre-war (or should I say fade) Karate styles (usually) having only two kanji such as Goju-ryu (剛柔流), Shorin-ryu (小林流), Uechi-ryu (上地流), Isshin-ryu (一心流), Matsubayashi-ryu (松林流), etc. Of course there are exceptions, Shotokan-ryu (松濤館流), Shindo Jinen-ryu (神道自然流), but they are in the minority.
When I think it through, if there was no option but to use style names, I wish Kyoda Juhatsu had simply named his style ‘Kyoda-ryu’ (許田流) and for that matter, every other teacher named their Karate after themselves: Miyagi-ryu (宮城流), Chibana-ryu (知花流), Shimabukuro-ryu (島袋流), etc. Subsequently their students would name what they do after themselves. Sure it might make tracing lineages a bit harder, but it would reflect more accurately what people are actually practicing.