At 7:55 a.m. on February 12, North Korea fired a medium-range ballistic missile into the Sea of Japan. LDP's Headquarters for North Korea's Nuclear Tests and Missile Launches (Chairperson: Secretary-General Toshihiro Nikai) immediately convened the Emergency Response Board to hear from relevant ministries and agencies about the government's response. The next day, the Headquarters held a full session to discuss future actions.

According to North Korea's state media, the missile was based on the submarine-launched ballistic missile (SLBM) used last August with improved performance, a new solid fuel-based engine, and a mobile launcher on a caterpillar-track. In the view of the Ministry of Defense, "It is an incontrovertible fact that North Korea is improving the precision, range, and stealth of its missile development technology."

In addition to sanctions under United Nations Security Council resolutions, Japan has imposed its own sanctions on North Korea, and members in attendance at the Headquarters meeting called for a new and more effective response as well.

The Party's National Defense Division (Director: Minoru Terada, Member of the House of Representatives) and Research Commission on Security (Chairperson: Hiroshi Imazu, Member of the House of Representatives) also held a joint meeting on February 15 to confirm their policy of accelerating discussions on enhancements to Japan's Missile-Defense System.