6 Detective Boys Members in the Detective Conan Series
Before Conan arrived at Teitan Elementary School, Ayumi, Genta, and Mitsuhiko were already close friends. They enjoyed playing together and were inseparable. When Conan joined them, the Junior Detective League or Detective Boys was formed, and they set out to help others in need.
When Ai Haibara joined the group, she wasn’t really a child but was forced to play along and become a part of the League. Despite their age, these kids often help solve cases with their curious behavior and teamwork.
How the Junior Detective League Started
In the first volume of the Detective Conan series, after Shinichi turns into Conan, Professor Agasa enrolls him in school so he can blend in and gather information without drawing too much attention. That school was Teitan Elementary.
When Conan first entered class 1-B, he was a bit of an outsider because of his unusual name. But he didn’t mind being on his own. One day, a girl named Ayumi Yoshida invited him to explore a mysterious house in the neighborhood.
The house had a dark history, involving an unsolved murder. During their exploration, Conan ends up solving the old case. Impressed, Genta, who saw himself as the leader of their little group, decided to recruit Conan into the Junior Detective League.
Later on, a new girl named Ai Haibara (the shrunken Shiho Miyano) joined the school. She immediately gravitated toward Conan because she knew his secret—both had been shrunk by the same experimental drug while she was still involved with the Black Organization.
At first, Conan was angry when he knew about Ai’s past, but after she explained her situation, they became friends. This led Ai, the usually cold and distant girl, to reluctantly join the Junior Detective League, along with Ayumi, Genta, and Mitsuhiko, eventually becoming part of the gang.
Core Members of the Junior Detective League
1. Conan Edogawa/Shinichi Kudo
Conan is the smartest and wisest member of the Junior Detectives, which makes sense because while he looks like a child, his mind and skills belong to Shinichi, one of Japan’s top young detectives. He is a role model for the other members and the one who usually makes the decisions.
Sometimes, Conan acts too mature for his supposed age, so he has to pretend to talk and behave like a 7-year-old, often saying things like, "Huh? Why…?" to blend in. He’s very protective of his friends and has even put himself in harm’s way multiple times to keep the group safe.
2. Ai Haibara/Shiho Miyano
Ai struggles to act like a child and always seems much older than her peers. In fact, Ayumi, who is the same age, calls her "Big Sister" instead of by name. Similar to Conan, Ai is often used as a reference point by Genta, Ayumi, and Mitsuhiko.
Despite her cold demeanor, Genta and Mitsuhiko are both scared of her, though Mitsuhiko has a crush on Ai, even though she never returns his feelings. In Detective Conan Vol. 77, Ai temporarily returns to her adult form after taking an antidote to APTX-4869 in order to save Genta, Ayumi, and Mitsuhiko from a fire.
3. Genta Kojima
Genta is large for his age and sees himself as the leader of the Junior Detective League. His favorite food is grilled eel rice, and he’s always snacking, much to Ayumi’s frustration. Genta relies mostly on his physical strength since he’s not very academically inclined, especially when it comes to reading kanji.
He can be reckless at times, even putting himself in danger because of his impulsive behavior. But like Conan and Mitsuhiko, Genta is very protective of the group. He’s reliable, follows his parents' guidance, and is always eager to lend a hand in solving cases, even if it means putting himself on the line.
4. Ayumi Yoshida
Ayumi is the cutest member of the Junior Detective League, and despite being the youngest, she has a big love for adventure, especially when it involves treasure hunts. She brings a cheerful energy to the group, always lifting everyone's spirits when they’re feeling down.
Ayumi was the first to invite Conan to join the Junior Detectives and often hides behind him when things get scary or dangerous. This is partly because she has a crush on Conan. Though she’s young, her simple observations often turn out to be key in solving cases.
5. Mitsuhiko Tsuburaya
Mitsuhiko is the brainiest of the Junior Detectives. In many subjects, even Conan and Ai can't keep up with him. This isn’t surprising since both of Mitsuhiko’s parents are teachers. He loves reading science books and is always polite, thanks to his parents' strict upbringing.
Because of his intelligence, Mitsuhiko sometimes comes across as being overly mature, almost like a young Conan or Ai. Still, he’s just a 7-year-old, and his insights often help solve cases, even when adults don’t take him seriously. Mitsuhiko has a crush on Ai, though she doesn’t feel the same.
Additional Members of the Junior Detective League
Aside from the core members, the Junior Detectives have an unexpected addition to their group—none other than their homeroom teacher, Mrs. Kobayashi. Even though she’s much older, she sometimes acts just like a kid when it comes to investigating cases with the children.
1. Sumiko Kobayashi
Sumiko Kobayashi was originally a substitute teacher for class 1-B. At first, she seemed strict, but later it became clear that she actually had a sweet and caring personality. Her tough attitude was just a way for her to build confidence. She truly loves children and is protective of them, though the Junior Detectives often tease her for being nervous in certain situations.
She joined the Junior Detectives as their supervisor, believing the kids needed an adult to watch over them and keep them safe. This won the admiration of Inspector Shiratori from the Japanese police. Known for being extra careful in everything she does, Kobayashi has a soft voice and a kind heart.
Now you know that the Junior Detective League doesn’t just have five members, but six! While Mrs. Kobayashi doesn’t always join their adventures, she’s always ready to support them whenever they need her. So, who’s your favorite member?