I just bought this vintage Bianchi road bike and was trying to find out more about it. The serial number is ES426771. It has Shimano 105 rear derailleur and shifters, a Suntour Arx front derailleur, and a Sakae crank. I'm guessing from what's been posted above that it is maybe from 1984 and made in Japan. Any other insight anyone might have would be very much appreciated!