The 47-year-old Grammy winner and her 34-year-old lover were spotted leaving Mastro's Steakhouse hand-in-hand, reported People magazine.
Carey wore a short, plunging black dress with large black belt for the outing and Tanaka coordinated in olive green pants and a black V-neck sweater.
She accessorised her look with an oversized red handbag, black stockings, black shoes, diamond hoop earrings and a matching bracelet - while he kept his look simple with back sneakers and diamond stud earrings.
The two had begun their whirlwind romance after Carey called it quits with fiance James Packer in October. The pair parted ways in April.