Looks like an American Eagle Semi-pro, circa 1971-2. I had one, my upgrade from a Schwinn Varsity. I convinced my parents to pay 1/2 for my Christmas present. I think total price was around $220. Mine was also yellow. I remember the way the seat stays taper and wrap around the frame. Suntour derailleur, Sugino crank, Dia Compe center pull brakes. Suntour ratchet bar end shifters. I think the change to the Nishiki name started in 1972.