Casino Gui handles two kinds of stories, one is about the in-fighting found within two warring factions of the same yakuza clan, the Date Clan, and the other is about gambling through the perspective of Gen, our protagonist, who, after his plan to rob a dark casino is thwarted, gets used as a sacrificial pawn for one of the faction's interests, the Kuronomiya group. Gen needs to climb through the ranks of casino dealers before the return of Kuronomiya's leader, failing to do so spells demise for him and his loved ones.
I think it does a perfectly decent job of delivering exciting gambling matches as well as raising interesting questions about the underworld the clan operates in. As you slowly connect the dots the story becomes a clash of whose desire to come out on top is the strongest. Not all characters are as fleshed out as the others. Once we get to a certain point in the story the manga skips some interactions between characters I would've liked to see. Still, overall it does a serviceable job of making you understand where everyone stands in the two opposing sides of the clan.
Something that truly hit the nail on the head for me was the art, characters are rarely rendered in bizarre or outlandish visual metaphors or expressions but once they do they highlight the intensity of emotions the characters feel which is one of the most important aspects in gambling manga, to accentuate utter defeat or a seemingly implausible win.
It's not a long manga but it achieves what it promises in the first chapters, in particular, the last "arc"/match shows glimpses of what could've been an entertaining one-on-one style of gambling we didn't see our characters in, similar to other gambling manga peers, as most of the story centers on Gen's role as a dealer in different variations of games using a standard deck (but mostly Baccarat). Once they start bringing other casino game staples the manga ends. That lack of departure standard games is what is holding back a higher score in my book as it feels like it had potential for an extended narrative for different foes and gambles to enter but other than that it was an enjoyable read, which makes me want to check out Bakuchi Gui by the same duo behind this story, once it gets translated (hopefully).