Episode 4

Adult Time is the fourth episode of the Assassination Classroom anime series. The episode first aired on February 6, 2015.

Overview
An assassin named Irina Jelavić is hired by the government and comes to Class E as a new teacher. She arrived early and shows her skills as a honey trap infiltration assassin. Could this honey trap kill the Venus Flytrap that is Korosensei?

Summary
Korosensei finishes his shopping at a market store when he sees a group of men harassing an attractive female foreigner. He easily disposes the men and the female thanks him and asks for directions to Kunigigaoka Junior High.

At Class 3-E's mountain classroom Karasuma introduces the female to be their new English teacher Irina Jelavić. The class immediately see that Korosensei is attracted to her due mainly to her exposed busts and that Irina seems to be in love with him in return for the earlier gratitude. Throughout the morning, Korosensei gets distracted from his teachings by Irina, coming up to him with various requests. During lunchtime, she gets him to order some Vietnamese coffee, which Korosensei instantly travels to Vietnam. Once gone however, Irina drops her act to the students and displays her confidence in killing Korosensei. Her attitude however puts off the class, Karma even going so far as to call her Ms. Jela -Bitch. Irina then sees Nagisa and kisses him, much to the class's shock and amusement, demanding to know all the weaknesses he has noted down so far, while she discusses with her henchmen for the assassination.

The class's first "lesson" with Irina is spent with the students looking at Irina while she plans for the assassination. From Nagisa's notes, one of Korosensei's abilities is his knack for smell, able to smell sweets from afar. Fed up with doing nothing, the class complain for Ms Jela-Bitch to teach them something. The repeated name-calling forces Irina to discipline to class and "teach" them how to pronounce the letter "v" for the entire lesson. The entire class declares this to be the "lamest lesson ever".

The next day, Korosensei returns and Irina asks him to come to the store shed for a private moment. Both the class and Karasuma watch on. Irina lures him inside the shed, and on the pre tense of undressing herself, hides behind a curtain while Korosensei is fired upon with various light machine guns. Coming out of her hiding spot, she is surprised to find her henchmen unconscious and Korosensei completely unharmed. He explains that not only were the lead bullets Irina used for the machine guns ineffective but he also detected the body odour of unfamiliar adult men. He realised early on that Irina was setting a trap and Korosensei pretended to have fallen for her. Korosensei punishes her by grooming her (Irina's sexual groaning loud enough for the entire class to hear outside), dressing her into a gym outfit and "doing that thing with his tentacles". When a suspicious Nagisa asked for clarification Korosensei makes a vague answer.

Back in class a humiliated Irina plans to get revenge. Once more the class asks her to teach something in preparation for their upcoming mid-terms, otherwise they'll get Korosensei to teach them. Irina responds by insulting the class that they care more for this exams than killing a being who would destroy the entire planet, and even if Korosensei is killed, their current status as Class 3-E students would discriminate them in their future lives. The class riots against her bitchiness as a result and a shocked Irina vows to kill them all.

In the staff room, Irina complains to Karasuma that she is an assassin, not a teacher who has to babysit 25-odd students. Karasuma later takes her to Korosensei sitting down and preparing individual tests for each student. Seeing how happy the students are because of Korosensei's methods, Irina begins to have second thoughts about leaving. Later on, Irina walks back into the classroom. She writes the sentence "You are incredible in bed" and has the class recite it in English. Using her experience as a somewhat questionable example, she explains how being able to have a conversation with someone and knowing the language is important not just in assassinations, but also in real life. Irina also takes the moment to apologise to the class for her rude attitude and insults. At this the class laughs, seeing how Irina completely turned around having earlier vowed to kill them. In return the class instead starts to call her "Bitch-sensei" (Professor Bitch), much to her chagrin. Outside the classroom, Korosensei believes that Irina will fit right in with the assassination classroom.