Jougorou Kobato has a habit of inserting himself into other people's problems. After realizing his detective skills are neither wanted nor appreciated, he makes an agreement with his shy friend Yuki Osanai to become ordinary together. Now entering high school, they aim to be perceived as regular people, yet Kobato cannot help but fall back into his deductive ways when faced with everyday mysteries. Unfortunately, mundane occurrences are not all the duo stumbles across. As they go through their school days trying to avoid drawing attention to themselves, Kobato and Osanai at times get caught up in incidents that put their plan of a peaceful, average life at risk. [Written by MAL Rewrite]

First-year student Takahiko Urino aspires to write something truly original for the school newspaper, Furnado Monthly. Encouraged by his girlfriend, Yuki Osanai—a seemingly average second-year student—Urino convinces the newspaper club to let him pursue an unusual story. A case of small-scale fires has escalated into serial arson, and Urino intends to predict the locations of future fires and identify the culprit. But his obsession with the case does not always reflect well on the club, and Osanai may not be so fond of her boyfriend's growing arrogance. Meanwhile, another supposedly unexceptional student, Jougorou Kobato, spends uneventful days with his girlfriend, Tokiko Nakamaru. However, when he witnesses a fire tied to a past case and Osanai herself, Kobato cannot help but slip back into his old, less-than-ordinary habits in search of the truth. [Written by MAL Rewrite]