Jigokuraku is currently known as the underdog of the "Dark Three", consisting of Akutami's Jujutsu Kaisen, Fujimoto's Chainsaw Man and obviously Kaku's Jigokuraku. The series never had it easy especially because of it's absolutely brilliant competetors but in my opinion it has still managed to establish itself as a series of it's own. Let me start by talking about the premise.
We start out at an execution site where a certain Gabimaru the Hollow is supposed to be executed by a swordswoman of the Yamada Asaemon clan called Sagiri. She tells Gabimaru about a voluntary mission issued by the shogun himself that if fulfilled shall grant one a pardon. Gabimaru wants this pardon in order to return to his peaceful days living with his wife after effectively retiring from being the most fearsome ninja to ever come out of the infamous village of Iwagakure. Gabimaru and Sagiri take on this mission with a bunch of other Yamada clan executioners and death row convicts. This mission is to venture to a certain Island that is said to be in posession of something called the elexir of life. This elixir obviously is the main goal of the mission but things are not quite as simple as it turns out. The Island is home to otherworldly creatures that resemble religious symbols and use some type of power that is unknown to us at the beginning of the story. We then get to see this entire Island be unravelled before our own eyes as the story progresses and we make our way toward the elixir without dying beforehand. This premise is what allows the story to feel different from the other two as it sets up a major mystery element right from the get-go.
Speaking of mystery, world building is the next aspect that I want to talk about. In short, it is absolutely brilliant and more than takes it's time. Everything feels natural and just helps the flow of the story. I won't get into detail about it but just know that there is always more to it no matter how much you think you already know.
Then there is the strongest aspect about the entire series in my opinion. The characters. What can I say... they are just amazing, from Gabimaru and Sagiri to especially Yuzuriha, Shion and Gantetsusai. Their dynamics are what makes the story as enjoyable to read as it is. Very funny but also serious moments in the face of danger. Speaking of danger, the lord Tensen as we know them also make for good villains. Definitely not the best nor most fleshed out especially when comparing it to Jujutsu Kaisen and Chainsaw Man once again but still worth mentioning.
Then there is the art. The art of Jigokuraku definitely is above average. It can be quite messy at times but more often than not you will be able to clearly see what is going on. Also the Author really got creative when it comes to the designing part. Everything looks incredibly unique and fresh.
I now want to talk about the ending. It was a pretty perfect ending in my opinion that left no one unsatisfied. Surely it was not some kind of genre defining masterpiece of an ending but it definitely cleared everything up and delivered us with execly what we wanted.

Now as for my personal feelings toward the story. I was really invested in the beginning of the story but slowly lost interest halfway through. That interest sadly only really came back at around chapter 95 thus resulting in myself not enjoying the middle part of the story as much as I could have because it was definitely not bad. Another thing that I noticed is how little I cared about the characters for the most part but in the end it still made me really sad to part ways with each and everyone of them (except for shugen, fuck shugen, all my homies hate shugen). I thought I hadn't grown attached to them but I found myself shocked at multiple occasions when a character I thought I didn't care about almost died or even actually did die. Oh god I am so fucking happy that Yuzuriha made it through the story, I just love her so much damn.
Well anyways, this will do it for this semi-long review and my thought on Jigokuraku. It is definitely a story that I will remember reading and am looking extremely forward to the confirmed anime adaptation. Well I guess all that's left to say is thank you Yuuji Kaku sensei! It has been a fun ride.