Yukina receives a letter from her missing brother, saying he wants to meet her, but overshadowing all that is the much more immediate bomb threat involving the four department stores in Shanghai known as the Big Four. The assailant lets Yukina read his mind, regarding the location of the three remaining bombs. While Aoi and Kazura search the other two stores to extinguish two of the bombs, Yukina and Natsume remain at the store where they are in to disarm the third one. It is revealed that the assailant is Kuse, who was sent to retrieve Yukina. Kuse is a subordinate of Isao with the abilities of teleportation and telepathy. To make matters worse, Aoi finds a young girl in one of the stores, also having to evade Kuse at the same time. As the four spies meet up with each other, Kuse retreats after being overwhelmed with their combined attacks.
