Formerly, Osumi Station was an unmanned stop equipped with a one-side platform with one track, which could only accommodate trains of up to four cars, but on March 23, 2002 it was renewed into a manned stop that could accommodate trains of up to seven cars; the renewed stop is equipped with two separate platforms and two tracks, and these facilities enable two trains to pass each other.
かつては、1面1線の4両編成までが停車可能の無人駅であったが、2002年3月23日より2面2線の7両編成までが停車、行き違いの可能な有人駅となっている。