Volcanic soils in Japan were reclassified in 2017, with most falling under Andosols. Forest soil data supported this classification, with 20% of forest soils showing Andosol properties. Some forest soils had Andosol traits but were hard to classify. The Fulvic Andosols group was replaced with Humic and Brown-humic subgroups. This revision aligns with traditional forest soil classification. In conclusion, the new Soil Classification System of Japan for volcanic soils was validated using forest soil data.