http://defense-studies.blogspot.ru/2015/07/japan-defense-ministry-gives-details-of.html The Japanese government has allocated the budget and formally begun the process of constructing and adding a new subclass of Aegis destroyers to its existing fleet of Kongo and Atago class Aegis ships. This new subclass is officially called the "27DD". It is widely regarded as the second but a much improved batch of the JMSDF's Atago class destroyer (which in turn is the same improvement of Kongo). The two ships of 27DD will be commissioned in 2020 and 2021. (image : Japan MoD) According to the Japanese MoD's RfP to bidding contractors, the 27DD will incorporate a number of design changes compared to the first batch of Atagos. First, the hull of 27DD has been enlarged to an empty displacement of 8,200 tons compared to the original Atago's 7,700 tons. It is believed in the Japanese defense community that the enlargement of the hull was conceived in order to provide a necessary growth space for advanced naval weapon systems that are currently under development in Japan, and will be incrementally added to the ships' arsenal as they are developed -- such as railguns and laser point-defense systems. ... Eventually, the Japanese MoD envisions their new Aegis ships to be the first operating platform of an indigenous naval railgun and laser point-defense system that they are locally developing in Japan. The plan for the railgun armament was outlined in their recently published FY2015 defense budget report. (Japan MoD)"