Fast Retailing Co. opened a major Uniqlo outlet Friday in Shinjuku Ward, Tokyo, setting off a rivalry with clothing retailer Marui Co., which celebrated the opening of its flagship store there the same day.

The Uniqlo store, the casual clothing brand's seventh outlet in the major shopping district, occupies five floors in the Shinjuku Palette complex on the west side of JR Shinjuku Station and boasts a total floor space of 1,900 sq. meters.

The Shinjuku Marui Honkan outlet meanwhile has its own eight-story complex in the same area. Marui officials said it was designed to reflect the preferences of customers they surveyed.

One of the Marui outlet's major features is a rooftop garden that it says is unprecedented in scope and scale. The garden gives shoppers a place to relax even in the center of the bustling business and shopping district.

The two chain's bullish expansion strategies are overshadowing the sluggish operations of the area's venerable but sluggish department stores, including Isetan, Takashimaya and Mitsukoshi.