Most signboards in Malaysia are usually in the national language and the international language, whereas some are also in Chinese and Tamil, which are spoken by the 2 largest ethnic groups after the Malays.
Other than the 3 major races, we have another group which is collectively known as "Lain-lain", or Others, for want of a better word. This is usually referred to the indigenous groups in East Malaysia, the aborigines, the mixed-bloods, and perhaps immigrant groups too.
We all know that Malaysia is a melting pot, a colourful *cough* harmony *cough* of cultures and languages. What I didn't know was that the Japanese made up such a large part of it that its language appeared in signboards in KL Sentral. Or maybe they decided that those who take the public transportation consists only of those who can read English and Japanese.