Japantown, commonly known as J Town, is a historic cultural district of San Jose, California, north of Downtown San Jose. Historically a center for San Jose's Japanese American and Chinese American communities, San Jose's Japantown is one of only three Japantowns that still exist in the United States, alongside San Francisco's Japantown and Los Angeleā¦Japantown, commonly known as J Town, is a historic cultural district of San Jose, California, north of Downtown San Jose. Historically a center for San Jose's Japanese American and Chinese American communities, San Jose's Japantown is one of only three Japantowns that still exist in the United States, alongside San Francisco's Japantown and Los Angeles's Little Tokyo.