Takahara is a small stratovolcano located SW of Nasu volcano and NNW of Utsunomiya city in central Honshu. The basaltic-to-dacitic volcano is constructed within the Shiobara caldera. It contains a number of small lava domes, including the symmetrical Fuji-san, one of many conical volcanic mountains named after Japan's renowned Mount Fuji. Fuji-san is the youngest known volcanic feature of Takahara volcano and was formed about 6,500 years ago.

The Shiobara caldera was formed more than 10,000 years ago, and corresponds to the Otawara pumice-flow deposit.

The latest dated eruption of Takahara took place about 6500 years ago along the NW-SE-trending Yumoto-Shiobara fissure system within the caldera. Eruptions along this fissure initially produced the phreatic Takahara-Uenohara tephra deposit distributed primarily to the east. The eruption ended with the construction of Fuji-san lava dome.