The future of Sogo & Seibu, a loss-making major department store operator seeking a business turnaround, remains uncertain following its troubled sale to U.S. investment fund Fortress Investment Group in September.

The sale, orchestrated by its previous parent company, retail giant Seven & I Holdings, was marred by a heated confrontation with the Sogo & Seibu labor union, resulting in the first strike in Japan's department store industry in 61 years.

The labor dispute was fueled by concerns about the preservation of the department store business and job security under the management of the new parent company.