Masumi Sera

Masumi Sera (世良 真純), a Teitan High School Student of Class 2-B and High School Detective who has been hiding in various hotels with Mary Sera, is a supporting character in the manga and anime franchise Detective Conan.

Background
Seventeen years ago when Masumi's father before he disappeared after he instructed his family to hide in Japan where Masumi later was born. Her Oldest Brother Shuichi left Japan to study abroad in America in order to become an FBI Agent to investigate their father's apparent death. Masumi eventually meets Shuichi for the first time at a beach where she attempts to make Shuichi laugh because he doesn't seem to smile but fails.

She later moved abroad three years ago with her mother, due to learning that her father was apparently roaming London. Her other brother stayed in Japan.

Appearance
Masumi wears a grey fedora that used to belong to Shuichi Akai and a dark jacket which gives her an androgynous appearance. When she transfers to Teitan High, she gets rid of her fedora and wears female clothing. Her hair is dark, wavy, and short; it doesn't even touch her shoulders. Even then, she is rather tomboyish; Genta mistakes her for a man, and Sonoko comments she has a petite figure. Later, Genta, Mitsuhiko, and Hattori comment that her bosoms are rather small. Masumi also has an uneven tooth that shows when she smiles.

Personality
Masumi has a cheery, sociable, boyish personality and is well-liked by her classmates at Teitan High. On their first meeting, Masumi fails to correct Sonoko's mistaken impression that she is a man and even makes it worse by declaring that Ran is "[her] type". Her rather boyish appearance - especially in relation to her flat chest - is a bit of a touchy subject to Masumi, who claims that her mother's bust size is rather well developed and keeps expressing her hope that someday her own chest size will similarly change for her.

Masumi is quite quick-minded, coming up with clever plans and adapting them to sudden changes rapidly. Masumi seems to be prone to dramatics like most detectives are, but perhaps to a lesser degree than Shinichi or Heiji as she bluntly says who the criminal is without preamble. On the other hand, Masumi is tough to the point that she is willing to risk all to achieve a successful conclusion of a case. In one instance, she purposefully lured a hostage-taker into a sniper's sight with a smile, hoping he would be shot without showing any apprehension about his possible demise.

Bourbon Arc
Masumi first met Sonoko, Ran, and Conan on a bus after she was mistaken for a groper. After Sonoko declared Masumi was the groper, Masumi and Ran got into a fight, with Masumi's Jeet Kune Do holding even against Ran's karate. Conan and Masumi cleared up the misunderstanding by pointing out the real groper. Sonoko then mistook Masumi for a boy, an impression which wasn't helped by Masumi declaring that Ran was "his type". Masumi and Ran both discovered they were heading to the same hotel, about which Conan is less than pleased.

Trivia

 * Masumi Sera's Character is based on Natsuki Koshimizu, a Tomboy Detective who is also known as the "Detective Of The South".
 * Natsuki Koshimizu is popular among Detective Conan Fans, however, Gosho Aoyama could not recycle her as a protagonist so he created Masumi Sera instead.
 * Masumi Sera's Real Paternal Family Name "Akai" (赤井) which means "Red", comes from the Fictional Character Char Aznable, whose nickname is "Red Comet", from the manga and anime franchise Mobile Suit Gundam.
 * Masumi Sera's Real Maternal Family Name "Sera" (世良) comes from the Fictional Character Sayla Mass, from the manga and anime franchise Mobile Suit Gundam. Sayla is similar to "Sera" in Japanese Pronunciation.
 * Masumi Sera's Vehicle is a Blue Yamaha Artesia XT400.
 * Masumi Sera's Catch Phrase is "Case Closed", the Official English Anime Name of Detective Conan.
 * Masumi Sera used to read the "Night Baron Series" when she was young, a Mystery Novel written by Yusaku Kudo
 * Masumi Sera is right-handed.