A part of Japanese species of the genus Thiotricha Meyrick, 1886 are reviewed. Three species described by Omelko (1984) in the genus Cnaphostola Meyrick, 1918 are placed in combination with Thiotricha; Thiotricha biformis, T. angustellacomb. nov. and T. venustaliscomb. nov. These species are redescribed, and two new species, T. elaeocarpiella Kyaw, Yagi & Hirowatari, sp. nov. and T. flavitermina Kyaw, Yagi & Hirowatari, sp. nov. are described based on external morphological characters of adults and genitalia of males and females. Thiotricha chujaensis (Park, 2016), comb. nov. described in Cnaphostola from Korea, is newly recorded in Japan feeding on Mallotus japonica (Euphorbiaceae). One of the new species, T. elaeocarpiellasp. nov. has been associated with two different plants, Elaeocarpus zollingeri (Elaeocarpaceae) and Rhaphiolepis indica (Rosaceae). This paper presents the first comprehensive description of the morphology, pupal morphology and biology of species previously treated in the genus Cnaphostola and their relatives in Japan.