This four-character idiom means, "upper class" or "upper echelons of society." It is pronounced jouryuu kaikyuu. Jouryuu means upper and kaikyuu means level.
You've now found the staple t-shirt of your wardrobe. It's made of a thicker, heavier cotton, but it's still soft and comfy. And the double stitching on the neckline and sleeves add more durability to what is sure to be a favorite!
• 100% ringspun cotton • 4.5 oz/y² (153 g/m²) • Pre-shrunk • Shoulder-to-shoulder taping • Quarter-turned to avoid crease down the center