ABC-Mart's (TYO:2670) all-store sales grew 8.8% year-on-year in May, as sales performed strongly, mainly at roadside stores and commercial facilities in metropolitan areas, driven by an additional Sunday and public holiday compared with the previous year.

The retailer's existing stores also posted a 8.8% year-on-year increase in sales, according to a Tuesday filing on the Tokyo Stock Exchange.

During the month, summer items such as sandals and T-shirts performed strongly as some regions recorded midsummer days, the filing said.

The number of customers at all stores grew 3.3% while spending rose 5.3%.

At existing stores, customer count edged up 3.4% while sales per customer gained 5.2%.

The retailer opened one new store and closed two during the month, bringing the total store count to 1,115.