Smart Brain, once Japan's largest company, lost its power due to repeated internal conflicts and was placed under government control with the goal of exterminating Orphnochs. Mari Sonoda, who is living with Orphnochs at the Western Laundry Store Kikuchi, when Takumi Inui, who had disappeared several years earlier, reappeared.

During summer vacation Natsumi is busy studying for her entrance exams. One day, as a change of pace she plays baseball with her childhood friend, Yusho. He suggests that they invite someone else to join them but that makes Natsumi uncomfortable. The friend he was going to invite was her "former best friend" whom she had not spoken to in a while.