A high school girl, Sayaka Kudō was the bottom of the class. After a year, she improved her deviation value from 30 to 70, then passed Keio University that is considered one of the most difficult to enter in Japan.

Ryota is an unpopular writer although he won a literary award 15 years ago. Now, Ryota works as a private detective. He is divorced from his ex-wife Kyoko and he has an 11-year-old son Shingo. His mother Yoshiko lives alone at her apartment. One day, Ryota, his ex-wife Kyoko, and son Shingo gather at Yoshiko’s apartment. A typhoon passes and the family must stay there all night long.

In the year 1868, three young men join the elite Shogitai division of the Shogunate. The Shogitai fights to the end and opposes the dismantling of the feudal military dictatorship known as the Bakufu system.

Graduating at the top of her class, elite detective candidate Jun Shibata is transferred to the section that handles cases deemed “unsolvable” by the department. Her partner, though a well-respected and experienced detective, has grown complacent after unsuccesfully pursuing these cases that many consider an exercise in futility. With her upper class breeding, her colleagues don’t expect much from her either, but she suprises them all with her motivation and astounding powers of deduction. Well-constructed mysteries and colorful characters abound in this stylish and edgy police drama.