Near Hachimansaki in Fukuoka prefecture a pleasure boat carrying a family of four has capsized. The parents are rescued right away, but the two young children are nowhere to be found. Traveling through the 7th district's waters, the Coast Guard ship Nagare heads to the area. It is there that our hero Daisuke Senzaki comes to a shocking realization. What if the two children aren't missing, they're—-!? Will he be able to show true courage and be the hero!? Daisuke is caught in a life or death situation that you can't miss!!!