Tsuritama is proof that anime is a medium rather than a genre, and that pretty much any genre will get a run sooner or later.
In this case it is fishing as the answer to an alien apocalypse. Or as it says on the cover of the local release: Saving the world one fish at a time.
Although it might be more accurate to say saving the world one person at a time, so I’m going to talk about some of the lead characters first (spoilers start here).
Tsuritama has a fascinating set of lead characters that will resonate with many viewers.
Yuki (“snow”) Sanada has never known his parents  and lives with his grandmother. Unfortunately, his grandmother has to move frequently and this has resulted in Yuki becoming completely unskilled at social interaction.
It has actually gone beyond that to a point where being faced with people can be overwhelming, and a feeling that he is drowning takes over. The drowning metaphor is convincingly incorporated into the animation and generates real sympathy for Yuki.
There’s a good example when he’s introduced to his new class as a transfer student and has to make an impromptu speech, which must be a close approximation to hell for many people let alone someone like Yuki.
About the first third of the series is devoted to Yuki’s growth as a person, and this storyline is well handled. There are hints about the looming apocalypse, but mostly it is about Yuki. In a sense Yuki is almost a male version of Mei from Say “I Love You”, and much of the payoff is the same .
Yuki doesn’t entirely get over his problems in the entire series, let alone in the first third, but there’s real character growth that is really quite satisfying to watch.
Meanwhile Natsuki (“summer” ) is in the same class as Yuki and is the accomplished angler that Haru and Yuki need as a teacher. His mother died two years ago, and Natsuki doesn’t accept his father’s growing relationship with Mariko. The strain in Natsuki’s relationship with his father is starting to tell on his younger sister Sakura (who adores Mariko but still deeply misses her mother).
Resolving this mess is the focus of the second third of the series (there is some overlap with Yuki’s story). I’m not going to spoil the details, but there’s a real heart to this section of the series that makes it worth watching.
As with Yuki’s story, Tsuritama doesn’t try to fix everything with a neat bow at once. This makes Natsuki’s story feel more natural, and strengthens it greatly as a result.
Saving the world (and Haru) by fishing
Yes, this really happens.
Yes, it makes sense in context.
No, I’m not going to spoil it beyond that.
For most of the early episodes Tsuritama doesn’t take itself, or Haru, particularly seriously. When that changes, it changes with a vengeance. Tsuritama goes to fairly dark places around episodes 9 – 11, but produces a good resolution in episode 12.
Possibly the best aspect is that Natsuki and Yuki have to save Haru  before they can save the world. This felt right given how Haru helped them earlier in the series. The final episode also features a nice easter egg just after the final end credits  that reinforces Yuki’s growth, but also highlights how far he still has to go.
I didn’t know what to make of Tsuritama at the beginning. The subject matter holds little interest – I don’t eat seafood at all, and I don’t have the slightest interest in fishing.
Despite that, and despite the strangeness of the set up, Tsuritama tells some interesting stories about characters that you want to care about.
Overall I’m going to recommend this as at least a “watch once”, and I intend to add it to my own collection .
EDIT: Here’s the rather odd opening credits (the dance is a plot point BTW)
 As a side note it is interesting that Mei’s story is a romance where Yuki’s story is more generally about comradeship. I suspect that there’s a raft of gender issues here that I don’t really have the skills to deconstruct.