According to the report of “The Employment Situations of Foreigners” issued by the Ministry of Health, Labor, and Welfare in October, 2018, 1.46 million foreigners are working in Japan (including full-time and part-time workers). Among them, 185,000 people (12.7%) are working at restaurants or accommodation facilities.
It is said that 10 to 20% of the restaurants in Japan have the staff who can speak English, and so you need to have more than basic Japanese skills as well as a proper visa for employment. Some restaurants may not require your proficiency in Japanese, if they have more customers from abroad or if you are a chef specializing in certain cuisine.
I will explain about different types of visa in the following part.