One-Punch Man is based upon the webcomic. The second season is 12 episodes long and it took four years in the making. It did change animation studios in the meantime and this is fairly obvious at times. The anime follows Saitama, who is probably the strongest human on Earth. He is able to destroy most (if not all when he gets serious) monsters with just one punch, no questions asked. Granted, he is a hero for fun and is bored with his immense strength since nothing is a challenge anymore. At the end of the last season, he had formally registered as a hero and is currently a Rank B hero (the top being Rank S).
Genos is Saitama's disciple, being a cyborg and more of your traditional powerful type. He's straightforward and uses brute force for most things. He's more serious and more akin to taking in the situation, understanding it and then formulating his response. The season begins with monsters attacking the cities with increasing frequency. It gets to the point that the hero association, who is in charge of organizing and deploying the heroes, is stretched for resources. It loses this focus midway through the season before picking the plot point up again in the ending. Compared to the first season, we don't get the monster-of-the-week structure anymore.
Even though he is a Rank B, fairly unremarkable as far as heroes go, Saitama isn't too concerned with his ranking or credit for defeating monsters. As the viewer and knowing his exploits and real powers, you feel that he should get the recognition he deserves. It's funny though when others in the hero association looks down on Saitama due to his rank but then there is the shock that undoubtedly occurs once they see his real power and how he is on friendly terms with various Class S heroes. The story is more focused and streamlined compared to the first season. While it does deviate from time to tie, especially when it shifts from focusing on something you thought was important. there is a very intriguing plot point surrounding everything that is currently happening.
Stronger and stronger monsters do appear and it seems to start exploring the weakness of the current hero system. There is what feels like an overabundance of heroes, with a typical executive team that's cowardly and useless. It reflects the red tape that is impeding everything. Garou is the deadly villain this time around and while he is wild with a run of the mill motivation, his craziness works. The bigger picture comes into focus after midway through the season. It is bigger in scope than just Garou picking off all the heroes one by one for fun. Unfortunately, the very beginning of the season teases, and you anticipate, the showdown between Saitama and Garou but they never truly cross paths and duke it out.
Saitama himself isn't as clueless as you'd expect. He speaks his mind and it is his honesty, as well as his lack of care (or indifference) that makes the anime funny. This season throws in some fairly intense scenes, with a fair bit of violence. Despite the childish (in a good way) tone at times, there are others where it is serious and it delivers an effective message. To the common folk, or even the the weaker heroes, it can be despairing when faced with an overwhelmingly powerful monster. All the time, you would be hoping for a hero (in our case, Saitama) to show but this might not happen at all.
There are obvious cost-cutting measures in place. There is an abundance of static images during "action sequences" with blurring effects and streak lines to make it more exciting without actually bothering to animate it. It loves to start a fight, then immediately skipping it to show Saitama winning. It's disappointing and kills the momentum whenever it does this. The season ends at a very bad point. It felt like midway through the arc and then it just suddenly ends. What makes this worse is that we don't get to see much of Saitama in action at all, which is a shame.
Overall, the second season of One-Punch Man isn't a disaster but it isn't a masterpiece either. There are obvious issues with it including the obvious cost-cutting measures. Despite that, it contains an intriguing story and a set up for a promising arc, it's just that it didn't have time to actually finish going through with it, opting to stop at an awkward spot instead.
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