Japan's imperial era system, however, is not without its critics.

Some maintain the Gregorian calendar should be used as the country's standard, with others stating that the antiquated system no longer reflects modern Japanese society.

"(Society here) is no longer controlled by an emperor," Hiroshi Kozen, a Chinese literature professor emeritus of Kyoto University and a member of the Japan Academy, told Kyodo News.

"The era system should reflect people's desire and we have to start from discussing why we need it," the 82-year-old was quoted as saying.

Others, including legal entities that filed a lawsuit last week at a local district court to try and scrap the "gengo" system, believe it violates the Constitution.

The era name changing with each imperial succession "destroys a sense of time held by each individual and violates Article 13 of the Constitution that guarantees all of the people shall be respected as individuals," the plaintiffs of the suit were quoted as saying.