Birthday: October 10
Age: 20
Height: 170 cm
Weight: 50 kg
Occupation: professional hitman, part-time foreign language teacher
BWH: 97-60-91

Irina Jelavić is a professional hit-woman who is hired to kill Korosensei by becoming a part-time foreign language teacher in class 3-E. She uses her charms to seduce Korosensei, making him at first obey whatever she asks. However, her first assassination attempt was foiled when Korosensei was able to suppressed her three-men attacks, ending in her humiliation, for which she then swore revenge. She teaches the students how to seduce people from other countries, so that with this method, they can learn foreign languages. She usually punishes male students who failed to answer her questions during her lesson by kissing them.

Irina is a deceitful, wily, and beguiling individual; she frequently uses her charm to influence and manipulate her targets. She can easily befriend people if she so chooses and entices them to let down their defenses and become vulnerable to her. Seduction is primarily the technique she employs, and it is her area of expertise.

Irina is a professional assassin who excels at handling infiltration and approaching targets. She possesses strong conversational skills in ten languages and has a proven track record of 11 jobs in countries all over the world. She boasts of her own capability and greatness; she has passionately stated that others in the same room as her should be grateful. Irina looks down on others, especially kids, who she believes are not commensurate to her excellence in performance. Her haughtiness is often considered detestable, and she particularly clashes with the students of Class 3-E. However, when enlightened of the necessity to work together with the students and the significance of them, she corrects her condescension and learns to be more humble.

She is nicknamed Bitch-nee-san by her students since she prohibited them to call her by her first name. Later, she became Bitch-sensei after her students acknowledged her as their teacher. Note that she got her nickname "-bitch" from the end of her last name "Jelavić." Since Japanese often pronounce the letter "V" as "B," -vic become -bic/-bitch).