"Let's help each other and aim to become perfect ordinary citizens." Kobato, who once had a bitter experience through deduction activities known as "wisdom work," was determined to become an honest and humble citizen. He secretly formed a reciprocal relationship with his classmate, Osanai, who shared the same aspiration, planning to make their high school debut as ordinary citizens and lead peaceful days. However, for some reason, mysterious incidents and misfortunes keep coming one after another into their school lives. Will Kobato and Osanai be able to achieve peaceful days as ordinary citizens?