A Sinner of the Deep Sea, Vol. 3

by Akihito Tomi, Caleb Cook (translator), Chiho Christie (letterer)

Sinner Jo and boarder guard Akira make an unlikely team—but now their shared suspicion of lord Harujion’s “Mermaid Island Operation” has brought them together for a daring mission! Sneaking into lord Harujion’s residence, they will risk it all to discover the truth of his wicket plans... Ryuu, who has let herself become a pawn in the lord’s scemes; Jo, who leads the rebellion against him; and Yuki, the human who is tossed in the turbulent waters between them... Where will they all lay when this tsunami of a story crashes into its conclusion!?

Genres: Manga, Fantasy, Romance, Comics

210 pages, Paperback

Published March 25, 2025

About the author

AKA: Tomi Akihito, 冨明仁

Reviews

[Rebecca · Rating 4 out of 5]

For a story based on the original "The Little Mermaid," I think this ended better than we had any reason to expect.

[Mark · Rating 4 out of 5]

The rare three volume series that acquits itself relatively well; it got in, got its job done, then wrapped up. It’s definitely not perfect, but it doesn’t leave me with any lingering regret.

The other review for this I read really nailed it - this is a satisfactorily unsatisfactory ending. I guarantee that almost everybody who comes into this looking for the resolution to that love triangle is going to be miffed, but it’s not a big old let-down.

This is especially true of the climax, which I have to say is a very solid piece of action. By the point where we’ve given way to unabashed moustache-twirling villainy you’re primed and ready for a classic throwndown and this one’s nice and dramatic even with the brevity.

This story never wavered from what was most important - Jo. She’s the beating heart of the narrative and a fantastic character; seeing her do the right thing by her friends while it’s killing her inside is really expressed well.

Jo’s desire to be there for the people she cares about and the importance of standing up against people who just want to get revenge under the guise of survival are front and centre throughout. Plus some general ecological handwringing, which is also an important topic.

I really liked that they kind of throw in some whatever powers here, but a lot of them are based on actual marine life and their traits. That might not help the grand scheme make a lot more sense, but it smooths it over just enough.

It does suffer a bit from the usual three volume structure - there’s so much going on in this volume that it’s overstuffed at times. Here come the elite guards and the high council and a whole other character who’s got to get a bunch of page time (although said character really works with the narrative and I liked their addition).

Things that would be stretched out, probably too much so, in a longer manga get dealt with lickety split. I think the one place this really lets the story down is with the character of Maya, whose detestable ass deserved a more satisfying comeuppance.

Still, the fact that I’m not yelling about what a waste of time it was is a big step forward for something like this. It’s a good little series that did a solid job with what it was trying to do.

4 stars - somewhere between that and 3.5, really, but I think this got the job done and with minimal flaws compared to the usual failings of this type of short series. That’s worth the full 4 on its own.

[TendaiisNarrative · Rating 4 out of 5]

I am both satisfied and dissatisfied, and it's a terrible position to be in. On one hand, it honestly makes sense that it ended in such a bittersweet way, and I approve. On the other hand, I WANTED ROMANCE. Obviously, this is not a romance story, and it is not why I picked it up, but I was introduced to not one but TWO possible relationships, and I'm upset at where everything ended up because I got my hopes up. Despite my wants, I loved the introduction of Linlin's character, and this was a great addition to the story.

[Aura · Rating 4 out of 5]

I always love a compact, well-written series that doesn't overstay its welcome. The art is to die for in all three volumes, the story and the characters all fun and memorable in their own ways, and I found the mermaid society fascinating. There's enough world-building and mermaid lore to make the setting interesting, but not so much that it would have slowed down the story. Without giving anything away, I personally really liked the ending.

[Christina Mastoraki · Rating 4 out of 5]

Το τέλος ήταν πολύ καλό, όλο δράμα και υποσχέσεις. Η πλοκή εξελίχθηκε πολύ ωραία, η ιστορία της Linlin ήταν σοκαριστική, και η συνεργασία της Jo και της Akira ήταν πολύ καλή.
Το πρόβλημά μου ήταν με το ρομαντικό κομμάτι της ιστορίας. Ήθελα μια δραματική ιστορία μεταξύ του Yuki και της Ryuu. Δεν ήθελα να δω την Jo να μπαίνει ανάμεσα τους ή τον Yuki να την ερωτεύεται επειδή πέρασαν λίγο χρόνο μαζί.

[D.T. · Rating 2 out of 5]

I'm not against a "realistic" ending, but it still felt a little rushed. There's also no resolution romantically. Ryuu realizes Jo and Yuki have a connection, but nothing really comes out of it.

Maybe one more volume would've made it smoother. But the artwork was very nice, and the gaze didn't feel as lecherous as before. Harujion looked fabulous

[Ray Rappisi · Rating 5 out of 5]

A fantastic ending of a sadly too short series. Everything about it was done magnificently, artwork, story and plot. Maybe it’s only vice is its simplicity, but it didn’t bother me one bit. This series would make a perfect movie if done with a decent budget. Loved it!

[Jeremy Burson · Rating 4 out of 5]

The first two volumes was excellent. This final volume was good but it seemed to be rushed and the romantic feelings of the main mermaid Jo was brought up but didn't really come to fruition. Like an unrequited love that didn't get a chance.
Still enjoyed this volume.

[Sher · Rating 3 out of 5]

Oh okay

Maya is a creep ew.

The ending i didnt see coming i thought maybe the three would be a couple not just leaving Ryuu alone LMAO like she brought you to him Jo and now its you and Yuki okay there
🤣🤣