The holotype had been collected in December 1906 by Alan Owston on Mount Fuji.

Allen noted that it resembled the brown long-eared bat, Plecotus auritus.

"[4] In 1929, Nikolay Alekseyevich Bobrinski published that he considered P. sacrimontis as a synonym of P. auritus.

In 1938, Allen himself expressed doubts about P. sacrimontis as a species, saying "Bobrinski...is very likely right in believing the name a synonym of P.

[6] This was largely maintained until 2006, when Spitzenberger et al. revised the genus Plecotus.