Fast Retailing (TYO:9983) said Tuesday that UNIQLO Japan's same-store sales, including online, rose 13.1% year-on-year in May.

The increase was driven by strong Golden Week demand, the Thank You Festival, and solid performance from newly displayed and year-round products, thy company said.

Total sales across all directly operated stores, including online, jumped 15.5%. Customer numbers climbed 12.5%, while average purchase per customer edged up 0.5%, the company said.

The company opened one new UNIQLO store and reported no closures during the month.