Why do Conan and the Detective Boys call Ai "Haibara-san"?


Since a few months, I'm watching Detective Conan in Japanese with subtitles
(because only the first 308 episodes are available in German). After a few
episodes, I did some research on japanese names, since "-san", "-chan",
"-kun", etc. was confusing me.

I've noticed, that:

  * The Detective Boys call Conan "Conan- _kun_ ", which seems to be perfectly normal, according to [Wikipedia](https://en.wikipedia.org/wiki/Japanese_honorifics#Kun)

  * Genta and Mitsuhiko call Ayumi "Ayumi- _chan_ " (according to [Wikipedia](https://en.wikipedia.org/wiki/Japanese_honorifics#Chan), this is okay as well, since they are young children)

  * Hiroshi Agasa calls Ai "Ai- _kun_ "

But:

  * The Detective Boys (including Conan) call Ai always "Haibara- _san_ "

Why do they treat Ai, like she was an adult? Genta, Mitsuhiko and Ayumi can't
know, that Ai is actually an 18-year-old woman.




To expand [my comment](https://anime.stackexchange.com/questions/39164/why-do-
conan-and-the-detective-boys-call-ai-haibara-san#comment53241_39164), it's
because she's a transfer student and always act mature

[![Case Closed Chapter 398 Page
3](https://i.stack.imgur.com/IpjIG.jpg)](https://i.stack.imgur.com/IpjIG.jpg)

Ayumi tried to call her Ai-cahn several times but too afraid to do so

[![Case Closed Chapter 398 Page
4](https://i.stack.imgur.com/sZY2Y.jpg)](https://i.stack.imgur.com/sZY2Y.jpg)

But in the end, she was able to call he Ai-chan, but when the other called her
that, she refused

[![Case Closed Chapter 398 Page
18](https://i.stack.imgur.com/yTeWg.jpg)](https://i.stack.imgur.com/yTeWg.jpg)

Pictures taken from Case Closed Chapter 398 and 400




To expand [my comment](https://anime.stackexchange.com/questions/39164/why-do-
conan-and-the-detective-boys-call-ai-haibara-san#comment53241_39164), it's
because she's a transfer student and always act mature

[![Case Closed Chapter 398 Page
3](https://i.stack.imgur.com/IpjIG.jpg)](https://i.stack.imgur.com/IpjIG.jpg)

Ayumi tried to call her Ai-cahn several times but too afraid to do so

[![Case Closed Chapter 398 Page
4](https://i.stack.imgur.com/sZY2Y.jpg)](https://i.stack.imgur.com/sZY2Y.jpg)

But in the end, she was able to call he Ai-chan, but when the other called her
that, she refused

[![Case Closed Chapter 398 Page
18](https://i.stack.imgur.com/yTeWg.jpg)](https://i.stack.imgur.com/yTeWg.jpg)

Pictures taken from Case Closed Chapter 398 and 400

