Bungo Stray Dogs season 4 opens with a Detective Collaboration between Fukuzawa and Ranpo. They meet on their first day, and for Fukuzawa, Ranpo is a genius who needs a mentor to guide him in controlling his intelligence. Fukuzawa had initially decided not to work with anyone, but after meeting Ranpo, he realizes that Ranpo is suitable to become a great detective, although a detective must be armed. The Fukuzawa and Ranpo meeting marks the beginning of the Armed Detective Agency.
On their first day as detectives, Ranpo accompanies Fukuzawa as a guard during a theater performance where a murder was announced. With all the traps presented by the murderer, Ranpo manages to expose the entire murder plan in great detail in front of the audience. However, after the murder case was exposed by Ranpo, Mitamura, one of the conspirators, takes Ranpo away. Mitamura pretends to be a police officer who wants to take Ranpo to the station, but Ranpo knew Mitamura’s evil plan from the beginning. He followed Mitamura’s plan with a plan of his own. Eventually, Mitamura takes Ranpo to a safe house with five guards.
Initially, Mitamura tried to persuade Ranpo to join his organization, but in the process, Ranpo managed to get a lot of information from Mitamura about his organization. On the other hand, Ranpo intentionally prolonged the conversation while waiting for Fukuzawa, who he believed would come to save him. Before leaving with Mitamura, Ranpo wrote a message to Fukuzawa stating that Mitamura was his enemy and that he trusted Fukuzawa to come and rescue him.
Sometime later, Fukuzawa came to rescue him, but when Fukuzawa killed all the criminals in the safehouse, Ranpo was slapped in the face by Fukuzawa. Ranpo’s overconfidence in solving the case was a positive trait, but he also put his own life in danger. This was what made Fukuzawa angry and unhesitant to slap him. Soon after, Ranpo realized his mistake and tearfully apologized to Fukuzawa. This incident shows that no matter how great Ranpo was as a detective, he was still a child who needed guidance. On his first day as a detective with Fukuzawa, Ranpo learned the most valuable lesson.
In conclusion, the fourth season of Bungo Stray Dogs opened with an exciting detective collaboration between Fukuzawa and Ranpo. They worked together to solve a murder case, and although Ranpo had an impressive intellect, he was still inexperienced in being a detective. Fukuzawa shows his strong mentorship by guiding Ranpo and teaching him valuable lessons about what it means to be a great detective. The collaboration between the two characters creates an engaging and compelling story for fans of the anime series.