Do hosts accept non Japanese people and / or non Japanese speaking people?

Most do. Many of our hosts have lived abroad and speak foreign languages. One of the motivations for many hosts to be involved in WWOOF is to meet people from diverse cultures and backgrounds. If this is of concern to you you should ask this explicitly of hosts when you contact them.
WWOOF Japan  Honcho 2-jo, 3-chome 6-7, Higashi-ku, Sapporo, 065-0042  JAPAN
E-mail: Contact Form   Fax number from within Japan: (03) 4496-6370    Fax number from outside Japan: +81 3 4496-6370

WWOOF Japan LLP (Limited Liability Partnership)