The shoulder phone was Japan's first mobile phone terminal, sold by NTT in 1985. Officially the "TZ-802," it weighed about 3kg and was carried on the shoulder like a bag, earning its nickname.
Costs were prohibitive: 200,000 yen deposit, 26,000 yen monthly base fee, and calls at 10 yen per 6.5 seconds (about 92 yen/minute). Users were primarily executives, doctors, and real estate agents who needed mobile communication.
The shoulder phone introduced "carrying a phone" to Japan. Previously, phones were fixed building infrastructure. It opened the era of "calling anytime, anywhere." The 900g "TZ-803" handheld model followed in 1987, accelerating miniaturization.
NTT Docomo's 1991 establishment drove further size reduction. Through i-mode in 1999 and iPhone in 2007, we reached today's smartphone era. In about 40 years, the 3kg device evolved into sub-200g smartphones. See telephone evolution for the mobile phone timeline.