However, it became difficult to continue the business in its original form due to too rapid expansion, and Kuhara Mining, which was a core industry, was transferred to Yoshisuke AYUKAWA, his brother-in-law, in the end of Taisho period.
しかし、短兵急に事業を拡大したために無理が災し、大正末期に中核だった久原鉱業を義兄の鮎川義介に譲渡する。