In 1879, the Soma family reported to the Imperial Household Ministry to take Tomotane under custody, and did so for awhile, but eventually Tomotane was hospitalized to the Tenkyoin, a mental clinic of the time.
1879年に家族が宮内省に自宅監禁を申し入れ、以後自宅で監禁、後に癲狂院（現在の精神科に相当）へ入院。