Multi-Mind Mayhem: Isekai Tensei Soudouki is one of those stories that has a stronger concept than execution. Its premise is one that plays around with the conventions of isekai, taking the idea of a soul from our world being reborn in a fantasy realm and running with it. Bard is an unsuspecting (and probably unfortunate) kid who falls ill one day. That, it turns out, is because (or at least not helped by) two souls are busy entering his body. One is that of Oka Sanei Sadatoshi, an elderly samurai from the Sengoku period who, after a lifetime of war, is finally killed in a failed assassination attempt. The other is Oka Masaharu, a high school boy who is run down by everyone's favorite murder truck when he gets distracted trying to decide if cat ears or dog ears are better on girls. Once both of them realize that they're dead, they're not exactly thrilled, but more or less accept the situation. Sadatoshi takes the news better than Masaharu, which does make sense; after all, he's been surrounded by death for his entire career as a warrior while Masaharu best knows it from pop culture. Even though they died centuries apart, both somehow end up inhabiting Bard's body. It isn't explained, but it doesn't necessarily need to be for the story to work; what's important is that one poor kid suddenly gets a couple of freeloading souls.

This, more or less, gives Bard a terrible case of Dissociative Identity Disorder in a very fantasy sense. We're not entirely sure if Bard's original personality remains, which is a shame, because that would have been an interesting take on the reincarnation aspect of the story. Both Okas, however, very much retain their personalities and knowledge, so there are at least two disparate personalities trying to share one body. When the story gets going, Bard is a young teen and both of his piggybacking personalities are really making themselves known, somewhat to the confusion of those around him. Mostly this comes to light in the strange knowledge that he has, something that largely appears to come from Masaharu.

We can say this definitively because Bard's mother is a former mercenary with the truly unfortunate name of Maggot. Maggot is training her son in the sword, and Bard, while not terrible, also isn't good to the degree that we'd know Sadatoshi was in control of his body or sharing his knowledge. This is the most compelling argument that Bard himself is still in there somewhere, although it could just as easily be Masaharu who's the dominant personality in the body. Sadatoshi comes through in the application of Masaharu's knowledge; he was a money-hungry fellow back in the day, and it's his desire that Masaharu's modern know-how be used to get them a pile or twelve of cash. So while Masaharu may just have been happy to get more accessible sweets by teaching people how to refine sugar from sugar beets, Sadatoshi wants to use the skill to make them some money – which of course it does.

Since all of this arguably sounds like a pretty good time, it's important to note where things go wrong in terms of execution. The fact that we can't quite tell if Bard is still a factor is certainly one issue, but the overall pacing of the volume is a large problem. It flies along at too fast a clip, glossing over character relations (including between the two or three inhabitants of Bard's body) in favor of introducing side characters and a plot about a neighboring country that wants to take over Bard's father's lands. This tangles with the sugar beet plotline when Bard hires mercenaries to guard the beet fields, so they just so happen to be there when the opposing forces attack. It happens so quickly that it feels less like a well-thought-out story and more like a series of ridiculous coincidences, with very few consequences ever rearing their heads.

That, in fact, is the primary problem here: there are never any real consequences. Not for the many souls in Bard's body, not for the family dynamic, and not for the political or economic situations. Everything is simply brought up and left by the wayside as the book races onward, and that leaves the whole thing feeling very insubstantial. Why does Seillune care so much about Bard? Is there a point to Theresa beyond throwing in a predatory lesbian character? What's the deal with the beast people's cultural standard that if you touch someone's ears you have to marry them, which, judging by doggirl Selina's reactions, is definitely a real thing? The story doesn't need to be deep, but it does need to explain a bit more than it seems willing to. Coasting by on tinkering with tropes and general silliness isn't a “get out of plot" free card.

Given that this is an adaptation of the light novels of the same name, it could be that the fault lies less with the author and more with how the adaptation is being executed. And this really isn't without potential – the discovery at the end of the book that one soul or another may be able to take full charge of Bard's physical body has some interesting implications and room for hilarity, and the concept really is a lot of fun and may just need some time to get going. But lackluster art and breakneck pacing rob this of a lot of its entertainment value. It simply isn't as fun as the sum of its parts.