Stay Cool Kobayashi-san A River City Ransom Story — takes place sometime after River City Ransom. At the Reicho High School, where the big battle took place, the Big Four is studying under the leadership of Masao Kobayashi, which other schools fear. As a result of mysterious events, he meets a boy named Mizoguchi, who is actually a Time Adjuster, pursuing an evil organization that upsets the space-time balance. Upon learning that Kobayashi has a penchant for mysterious power, Misoguchi asks him to destroy the organization.