These are characters of the regular cast. Some of them are not introduced until much later in the series, but I still put them here because they eventually appear on a regular basis and become part of the regular cast.

A 17-year-old "mystery otaku." He's the son of a mystery novelist and an actress/idol. Both of his famous parents are living abroad in America, so he lives alone. He grew up worshipping the detective heroes of mystery novels, and aspires to be the modern-day Sherlock Holmes. His detective skills are second to none, and he was on his way to becoming a famous detective when he was poisoned by two men in black of an underground crime organization. The poison didn't kill him; instead, it shrunk him into his 7-year-old body.

After Shinichi is shrunk, he's forced to pretend to be a 7-year-old named Conan Edogawa. While he hasn't figured out how to permanently return to his grown-up body yet, he does return to Shinichi form temporarily several times in the series. You have to read those cases to find out how that happens. Those cases are marked in the Manga Breakdown section.

Shinichi's hobbies include soccer and reading mystery novels. His romantic interest is Ran, the girl he grew up with. Ran doesn't know about his secret, and thinks he's just away on a case. Shinichi is forced to carry on this lie when he moves into Ran's house under the guise of Conan Edogawa.

The name Conan Edogawa comes from combining the names of Sir Arthur Conan Doyle (famous English mystery writer and creator of Sherlock Holmes) and Edogawa Rampo (famous Japanese mystery writer and creator of Kogorou Akechi).

Conan is Shinichi's alter ego. He may appear to be a little kid, but he still has the mind of a 17-year-old. He lives with Ran and her father Kogorou in their house/private detective agency. As a result, Conan comes into contact with various cases and helps Kogorou solve those cases. Along the way, he's hoping to obtain leads on the whereabouts of the two men in black who poisoned him.

Being in a child's body makes things difficult for Conan. People don't take him seriously, he lacks adult strength, and he's constantly worried about his secret being revealed to the wrong people. In all this, he's helped by his old neighbor Professor Agasa, who invents all sorts of gadgets to help Conan stay undercover and solve crime. In most cases, Conan has to use the voice changing bow-tie and tranquilizer watch to knock someone out and make him/her "voice" his deductions.

Shinichi's childhood friend slash love interest. She's the daughter of a private detective and a lawyer. Her parents are separated, and she lives with her father, Kogorou. Their house doubles as his detective agency.

Ran's in love with Shinichi, and ever since he disappeared after their date at the amusement park in chapter 1, she's been missing him. Ran agrees to take care of Conan upon meeting him (not knowing that he is in fact Shinichi), and she treats Conan like a baby brother of sorts, to the point of taking a bath with him at one point 0_0; However, she has made the Conan = Shinichi connection several times only to be proven wrong in the end somehow.

Ran is very kind-hearted. While many characters dismiss her as a silly girl at first, she always end up winning them over with her big heart.

Ran plays the damsel in distress in some cases, but her expert karate skills also allows her to save Conan's butt several times.

Ran's father. An ex-cop turned private detective. His wife left him, partly because of his skirt-chasing and drunken ways. He does have his moments though. He's good with judo and pulls a mean Ipponzeoi.

Kogorou's deductions are almost always wrong, and it's up to Conan to tactfully point him to the right direction without arousing suspicion. Think of him as the Inspector Gadget to Conan's Penny & Brain.

Kogorou is Conan's favorite "explanation puppet." When Conan has figured out the case, he uses the tranquilizer gun on his watch to knock Kogorou out, and through the voice changing bow-tie, speaks in Kogorou's voice to point out the killer and explain his deductions. Kogorou happily takes all the credit after he wakes up. After much success this way, Kogorou has gained a reputation as "The Sleeping Detective" who solves cases in a trance.

I think he's named after Kogorou Akechi, the Japanese Sherlock Holmes of sorts.

Neighbor to Shinichi's family house. He's good friends with Shinichi's parents. He's also a jolly inventor who designs all sorts of gadgets to help Conan with his detective work. Those gadgets include the voice changing bow-tie, the power-kick shoes, the tranquilizer watch, turbo-engine skateboard, just to name a few.

Basically, Professor Agasa is Conan's go-to guy and always ready to help. He eventually becomes Ai Haibara's guardian.

Professor Agasa drives an old Volkswagen Beetle, and enjoys taking Conan, Ai, and all "The Detectives Boys" to camping trips.

Ai may look like a child, but she's actually a scientist who took the same drug as Shinichi and shrunk into a child. She used to work for the "Black Organization" under the code name Sherry, and developed the experimental poison called APTX-4869 that caused her and Shinichi to shrink.

Her sister Akemi Miyano worked for the same organization, and was killed by Gin & Vodka in the "1 Billion Yen Robbery" case. After her sister's death, Ai tried to get out, so she took the drug and shrunk herself to escape. All data relating to the APTX-4869 drug were destroyed afterwards.

Ai ends up living with Professor Agasa, and offers a sardonic presence to the series.

The name "Ai Haibara" is not her real name (her real name is Shiho Miyano); she and Professor Agasa made up "Ai Haibara" from names of famous female detectives like Cordelia Gray and V. I. Warshawsky (the same way Shinichi came up with "Conan Edogawa").

First appearance: vol.18 file.6 in the "Fake Bills" case.

The police figure. He's slightly more competent at catching the bad guys than Kogorou.

Most of the time, he's there to put the bad guys away after Conan figures out the case.

A higher level police officer who works with Megure, Satou, and Takagi.

He competes with Takagi for Satou's affections, and uses every trick in the book to try to sabotage their chances at romance.

First appearance: vol.21 file.8 in the "Murder During A Phone Call" case.

A young female police officer working for Inspector Megure. She's bright and attractive, but a tomboy at heart.

She has many male admirers in the force; Officer Takagi and Superintendant Shiratori are both rivals for her affection.

Miwako's father was a policeman, and died on the job. Her late partner Junpei Matsuda was also killed on the job.

First appearance: vol.19 file.10 in the "Soccer Game" case.

A young police officer working for Inspector Megure.

He gives off the impression of a bumbling fool, but he can also be quite sharp when he's focused on a case. He nurses a crush on Miwako Satou.

First appearance: vol.21 file.8 in the "Murder During A Phone Call" case.

Ran's best-friend. She's part of the wealthy Suzuki family empire.

Through her family connections, Conan & Ran get invited to a lot of exclusive events, where many elaborate murders just happen to take place.

Sonoko is always on the prawl for a boyfriend, but due to her bad taste in men, she has been unlucky in love. No guy has given her the time of day, except for karate champ Makoto Kyougoku.

One of the kids Conan befriends in grade school. He's the big tough guy of the group, and he's very protective of Ayumi. He has a crush on Ayumi.

Ayumi

She's the token girl of the group. It's been implied that she has a crush on Conan.

He's the smarter one of the group. He also has a crush on Ayumi.

Genta, Ayumi, and Mitsuhiko love to copy Conan's lead and play detectives (much to his dismay). They eventually receive "Detective Boys" transmitter badges from Professor Agasa (in the "Missing Body" case) so they can communicate with each other, and they started calling themselves the "Detectives Boys," even though Ayumi is a girl.