The members of the Pretty Boy Detective Club: Manabu Sotoin, Nagahiro Sakiguchi, Michiru Fukuroi, Hyota Ashikaga, and Sosaku Yubiwa, along with Mayumi Dojima, visit the location where she saw the lost star ten years ago. The deadline imposed by her parents to stop searching for the star is quickly approaching. Meanwhile, she finds herself being tailed by a shadowy figure! She escapes from its evil clutches only to be told a shocking truth from the Pretty Boy Detective Club...

On their way home from school, Mayumi Dojima and Manabu Sotoin are abducted by a group that call themselves the Twenties. They are after a secret hidden within the star that Mayumi saw ten years ago. The remaining members of the Pretty Boy Detective Club take action to save their friends and finally face the Twenties in a battle! What will Mayumi's decision be after the search for the missing star ends?

The Pretty Boy Detective Club obtains an invitation to a mysterious casino called Reasonable Doubt. When they arrive at the casino, they find that all the patrons and employees appear to be middle school kids. The manager of the casino, Lai Fudatsuki, challenges Nagahiro Sakiguchi to a showdown, and if Nagahiro wins, he acquires the right to operate the casino!

Nagahiro loses to Lai, but the Pretty Boy Detective Club figures out the trick that Lai used to win. In order to battle Lai again, they sneak into the Reasonable Doubt Casino. But at the moment of the showdown, the detectives are met with an unexpected situation! What will be the outcome of the battle between the rival middle schools?

During the renovation of the Pretty Boy Detective Club headquarters, the team finds thirty-three paintings in the attic. The mysterious paintings appear to be based on works by legendary painters but are missing human figures. Who created these paintings and for what purpose? While the members of the Pretty Boy Detective Club each present their own theories, they find their way to the person who created the paintings...

The artist who created the paintings found in the attic was a former art teacher named Kowako Towai. She was a suspect in a kidnapping case that happened seven years ago. How will the Pretty Boy Detective Club solve the mystery of the thirty-three paintings in the attic and the kidnapping case?

A huge oshie-hagoita from an anonymous sender suddenly arrives at the art room that has been transformed into the Pretty Boy Detective Club headquarters. The Pretty Boy Detective Club deduce that the sender was Kodaki Kawaike, a first-year student at Yubiwa Academy and Nagahiro's young fiancée. Contrary to her beautiful looks, Kodaki is feared by the Detective Club members as a demon...

The reason for Kodaki's strange behavior remains unclear, but her family background and an “incident” that occurred in the past between her and the Pretty Boy Detective Club becomes apparent. Nagahiro finally decides to break his engagement with Kodaki. What will be the fate between the girl known as the devil and the Pretty Boy Detective Club?

The student council elections are coming up at Yubiwa Academy Middle School, and Wana Naganawa, the current student council vice-president and leading presidential candidate, is forced to withdraw her candidacy after becoming the victim of a hit-and-run accident. The Pretty Boy Detective Club sense that there is a conspiracy behind the elections and begin their search for the suspect. They set up Mayumi as a new candidate to run in the elections but...

With the help of Odoru Sotoin, Manabu Sotoin's older brother and the founder of the Pretty Boy Detective Club, Mayumi steadily gains more supporters in the election. However, the Detective Club is unable to solve Wana Nagawa's hit-and-run case, let alone find any clues. The culprit behind the hit-and-run case is now targeting Mayumi and...!?

On the day of the elections for student council president, Kinshiro Yokuya, Mayumi's rival candidate and classmate, sits next to her. Before Mayumi's speech, Kinshiro sets his last trap...! Will the Pretty Boy Detective Club be able to protect Yubiwa Academy?