Prime Minister Fumio Kishida on Wednesday made a surprise announcement that he would not be seeking reelection in next month's Liberal Democratic Party presidential election. As a result, the ruling party will select a new leader and the country will have a new prime minister.

Considering there is another full year left before the current term of the Lower House expires, Kishida’s announcement has many wondering why. To make sense of the situation, here are five points that may help.

The first is that although Kishida's sudden announcement may have been a surprise, the fact that he would be replaced this September is not. The average tenure for an LDP prime minister is only about 2 1/2 years — a mark that Kishida surpassed earlier this year. Save for a few outliers like Eisaku Sato, Junichiro Koizumi, and, most recently, Shinzo Abe, the party has tended to cull its own leadership to manage domestic support and internal party politics.