Most were based on various ways numbers could be read in Japanese.
One of the most popular services allows users to check train schedules and plan trips on public transit.
One example deals with the astrological symbol for Libra (♎).
It resembles a cooked and puffed mochi, and is sometimes used in a happy new year's message as mochi are often eaten then.
The wide variety of features, many original to or limited to Japan, lead to the term "Galápagos syndrome", as these resulting phones were dominant in the island nation of Japan, but unsuccessful abroad. There is some overlap of market segments between low-end smart phones and high-end feature phones, and many shared features.
PHS, which was initially developed as a cheaper alternative to 2G networks such as CDMA and GSM, was initially deployed in 1995, but is now only offered by one carrier, Y! As elsewhere in the world, smart phones have been growing extremely quickly.