The Japanese members of the proturan genus Gracilentulus comprise five species: G. aokii Imadaté, G. chichibuensis Nakamura, G. macrotarsus sp. nov., G. microtrichus sp. nov., and G. europaeus Szeptycki. In the present study, the new Gracilentulus species are described while G. europaeus is described based on Japanese specimens. Gracilentulus europaeus belongs to the "gracilis" group, which was recorded in Japan for the first time herein. Supplementary notes are provided on G. aokii and G. chichibuensis. A key to the species that lack sensillum b' on the foretarsus is also provided.