After having saved Aika Mihara's life in Aika Crisis, the story of Osamu Ashikaga continues in the new arc, War Cloud. This time, Osamu is reunited with yet another ex....who happens to be a WAR GODDESS?! Tsukiakari Senkumo returns after many years apart from Osamu, hoping to rekindle their lost love. However, she unintentionally brings her past along with her, endangering the lives of Osamu and his other exes. If either Tsukiakari or Osamu have any hope of countering the looming threat to their lives, they'll need to be honest about themselves to each other. However, Tsukiakari holds a terrible past within her, a bond of sorrow with Izanami, as well as a very uncertain near-future. The winter is the season of love, and also of harsh lessons. Osamu must decide, more than ever, what is truly important to him.