As the news reverberated throughout Japan earlier this month that Emperor Akihito intended to relinquish his throne while alive — in the first such move in about 200 years — the nation was struck by one of the biggest implications of his exit: the arrival of a new era.

The Emperor's abdication within the next few years, if true, would put an end to the current Heisei Era — introduced in 1989 following the death of his father, Hirohito (posthumously called Emperor Showa) — and usher in a new gengo, the Japanese term for an era name, for the first time in about 30 years.

The following is a look into gengo, Japan's unique way of identifying a year: