I called this the Civilization V manga. If you play Civ 5 you'll know Himeji Castle is a wonder of the world that gives massive bonuses to fighting inside your territory (might have changed again, been a while). Well, apparently zombies think this castle is overrated so they're attempting to seige Himeji Castle (and it might have an artifact that'll help the zombies, maybe) and it's defended by Miyamoto Musashi and some random boy who wanted to build castles when he's grown up. Although it's supposed to be your zombie stuff it somehow seems more like a comedy even with people getting their head chopped off or eaten by zombies. At the very start you see the zombie leaders discussing how to siege Himeji Castle and what's believed to be Mori Motonari suggested they should bribe people to attack Himeji Castle from within, because people will totally defect to the zombie side if you just talk to them. There's also this consistent theme of the castle building guy always saying "this trap in Himeji Castle will totally annihiliate the invaders" and then it'd be like "Oops this trap doesn't work well on zombies".
Later on it turned out if you kill the zombie leader then all their subordinates go away too, and to kill the zombie leader you have to destroy the artifact that summoned them back. So all the guys are fighting Uesugi Kenshin, who in typical Sengoku lore is someone who can easily defeat Goku in a fair fight, and it was like a standard "OMG all of us put together still has no chance of beating him" and then Kenshin decided he need to get his drinking fix (he's known to be a heavy drinker), and then they figured out that the cup he's drinking from must be the artifact so they smashed it and defeated a guy who is pretty much never defeatable in a straight up fight. Well, Uesugi Kenshin is always like the good guy in Japanese stuff, so I guess that's a good way for him to go. There's still Oda Nobunaga who is always involved everything demonic, and he also has a gun. I totally expect them to fight Oda Nobunaga in a sword fight and just when it looks like they're going to win he pulls out a gun, or maybe a rocket launcher, and blow people away, and it'd be like "No way the guy who is known for revolutionalize gunpowder in warfare uses a gun instead of a sword! How can this be possible?"
Later on it turned out if you kill the zombie leader then all their subordinates go away too, and to kill the zombie leader you have to destroy the artifact that summoned them back. So all the guys are fighting Uesugi Kenshin, who in typical Sengoku lore is someone who can easily defeat Goku in a fair fight, and it was like a standard "OMG all of us put together still has no chance of beating him" and then Kenshin decided he need to get his drinking fix (he's known to be a heavy drinker), and then they figured out that the cup he's drinking from must be the artifact so they smashed it and defeated a guy who is pretty much never defeatable in a straight up fight. Well, Uesugi Kenshin is always like the good guy in Japanese stuff, so I guess that's a good way for him to go. There's still Oda Nobunaga who is always involved everything demonic, and he also has a gun. I totally expect them to fight Oda Nobunaga in a sword fight and just when it looks like they're going to win he pulls out a gun, or maybe a rocket launcher, and blow people away, and it'd be like "No way the guy who is known for revolutionalize gunpowder in warfare uses a gun instead of a sword! How can this be possible?"