The termitophilous tribe Termitohospitini was discovered in Japan. Sinophilus yukoaesp.nov. and Japanophilus hojoigen.nov., sp.nov. are described from specimens collected in Nansei-shotô. The genus Sinophilus is redefined. These species are the first-discovered inquilines of Coptotermes formosanus Shiraki in Japan. This suggests that C. formosanus is native to Japan rather than an introduced species, as previously believed.