Of the two series to air in 2015 which focus on unconventional teachers helping troubled students (the other being Ultimate Otaku Teacher), this manga adaptation from the winter and spring seasons is the superior one based on nearly any measuring stick you could pick. Its artistic and animation quality indisputably far exceed those of its competitor, it has a far more likeable teacher character, it is funnier when it tries to be funny, it has better openers and closers, and it is even more creative in the ways its teacher works to help his students succeed. About the only place where its competitor even comes close is in its supporting cast of students, and even then Assassination Classroom is good enough. It is hardly a flawless series, and in the end it aims much more for entertainment value than depth, but which one is actually worth your time to watch is clear. The basic concept is one of those ludicrous ideas which can only happen in anime and manga: the teacher is an alien (or is he?) and the students are tasked with killing him before he destroys the Earth at the end of the school year. What saves the series from merely being relegated to eye-roll status is that Koro-sensei is an absolute delight from the first moment he appears all the way through to the end of the series. His bizarre character design virtually demands attention, but it is his character, and especially his eccentricities on display, which will keep it. The series suggests relatively early on that him picking the downtrodden Class 3-E was not random; he may, in fact, have been specifically asked to do it by someone he respected (or perhaps loved?). Whatever his actual motivation, and regardless of whether or not he actually does intend to destroy the planet at the end of the school year, he makes it repeatedly clear that he takes being a teacher very seriously. He is quite firm that none of the students' assassination attempts disrupt class or harm other students, he acts to protect them from harm when they are imperiled, and he praises them on creative attempts while also explaining in detail why they did not work. He uses his super-speed to his students' advantage, too, such as by helping out students who have particular problems (for instance, at one point he flies to a pro baseball stadium and studies a star pitcher's pitching motion to help one prospective baseball player), making elaborate study guides, and even personalizing responses to homework. The level of effort he puts into this is insane, the kind of thing that any secondary teacher wishes he had the time to do, but that just makes it all the more impressive.

Koro-sensei is also quite the character. His expressiveness is not exactly normal, to the point that one student keeps notes on how he reacts to things in an effort to learn to translate his weird visual cues, and unearthing his many peculiarities is a regular feature of the series. The absolute glee with which he approaches most things makes him fun to watch, and his sense of humor shows in things such as insisting on students making references to tentacles in writing assignments or the way he occasionally tries to disguise himself. By comparison, most of the recurring adults are (sometimes very exaggerated) caricatures and the students more often than not serve as the straight men/women. Only a handful of them develop much significant personality, chief among them the calm, studious, girly-looking Nagisa; the sharp-mouthed Karma; and bully/rebel Ryoma. The series does not exactly flounder when focusing on the others, and when working collectively they do accomplish some impressively innovative strategies, but they are clearly not the strength of the series, either.

The first dozen or so episodes of the series focus mainly on building the recurring cast, developing Koro-sensei's interactions with his students, various outside attempts to end Koro-sensei and his threat, and occasional interactions with the school's main campus. A short arc involving an academic competition with the main campus sets up the series' longest and final arc, a seven episode island excursion in which the most elaborate attempt yet to kill Kuro-sensei leads into a situation where many of the students' lives are endangered and the remaining ones must solve the problem themselves, as the assassination attempt has temporarily reduced Kuro-sensei to little more than observer status. That arc does drag things out a bit, and one or two episodes before that are yawners, but even then the series rarely stays down for long. It has a general tendency to be over-the-top, in a way not unlike what Akame ga KILL! sometimes is, but that is never really a hindrance to the entertainment value. After all, this is all pretty ridiculous anyway.

The visual production comes courtesy of studio Lerche, which is currently collaborating with director Seiji Kishi (Angel Beats!, Yuki Yuna Is a Hero) on Ranpo Kitan: Game of Laplace. The resulting visuals are quite sharp, including several interesting camera angles and a sense of depth in many shots that is rarely seen in non-CG productions. Character designs for human characters are fresh and attractive (when they want to be), if not necessarily always distinctive, and Koro-sensei is a visual treat. Use of color is pretty sharp, too, and animation quality is above-average when full animation is used. It is relatively clean in a graphic sense, too, as bloody violence is almost non-existent and the only character shown in sexy fashion is an adult female assassin who is portrayed as one of the world's top seductresses. The intensity factor, and the fact that this is, after all, a bunch of students trying to kill their teacher, are the only things that make it inappropriate for younger viewers.

The musical score provides a nice, effective mix of gentler piano tunes and orchestrated dramatic numbers, but the places where it really shines are in its openers and closers. “Hello, shooting star,” which is used for the entire 22-episode run, is a gentle, pleasant number with an adult contemporary flavor, while the opener changes up with episode 12 (i.e., when the series progressed into the spring season). Initial opener “Youth Savage Theory,” sung by the seiyuu for several of the principal students, is a catchy, enthusiastic number featuring all of Class 3-E dancing, and some of that animation was reused in the nearly equally enthusiastic “Self-Reliance Revolution;” I slightly favor the first opener because the second one feels like a retread, but they are close in quality.

Funimation started simuldubbing this series after a few episodes, and by the time of this writing the dub has now been completed through the final episode. The results are mixed. Sonny Strait (yes, the voice of Krillin from Dragon Ball Z) puts in a noble effort as Koro-Sensei but cannot quite capture the full style and verve of Jun Fukuyama's original performance; in fairness, though, the performance is hardly bad, and Fukuyama's take on Koro-sensei is both one of the most distinctive efforts of his voluminous career and one of 2015's best Japanese performances to date. Also a bit iffy is voice acting newbie Chris Ryan, whose rendition of government agent Karasuma never sounds quite deep-pitched enough for the role. On the good side, Lindsay Seidel is perfect as Nagisa and Martha Harms gets seductress Irina's attitude just right (although she makes no attempt to use the Russian accent that her character's name would suggest). The English script does retain a clever way to explain where Koro-sensei's name comes from (it's a play on the Japanese word for “unkillable”) and turns the “bitch” nickname the students give Irina into the equally fitting “yellow bitch” (it is close to Jelavic and she is blond).

The end of the series marks the end of an arc rather than any full sense of closure, and certainly some major secrets – such as why Koro-sensei is really going to destroy the world – have yet to be revealed at that point. Fortunately the series did well enough in ratings that a second season is expected out sometime in 2016. That will be a welcome continuation, as while the storytelling does have its soft points (especially in the middle) and does drags things out a bit too much in the final arc, to the end it remains interesting and entertaining enough overall to warrant watching more.