Pedzisa mutsara unotevera: Pashure pokudzokera kuPenang achibva kuEngland muna 1927, akabatana nekambani yemagweta yeLim &amp; Lim Advocates and Solicitors. Apo hondo yakatanga muna 1948 uye
MaJapan akapinda muMalaya, Oon akatiza ndokuenda kunogara muSingapore. Zvisinei, nokukurumidza Singapore yakawirawo muhusungwa hweJapan, asi apo vagari veAsia vakabvumirwa rusununguko, Oon akasarudza kushandisa rusununguko irworwo uye kupinza zvisiri pamutemo uye kuendesa tsamba kuvasungwa vehondo vaive vasungwa mutirongo reChangi.