Random Fact because I was confused by page 11 and knew nothing about crossbows (and 3 videos and many google searches later): The bow with the gears is what's referred to as a Cranequin Crossbow and yes if you are confused how it fires while hooked up to that crank/winding gear, you can remove the winder after notching the string. For a Cranequin, the winder isn't secured onto the crossbow and the crossbow body typically has a narrower stock and thickens as it approaches the front to secure (usually with a strap) the winder to the body while allowing for easy removal for firing.......don't ask me how they they remove the Cranequin with the wavy stock being thicker than the tiny corner of a strap you see on page 11, but in the pages before you can see the narrow stock on the crossbows. Personally with my amateur knowledge, a Goat's foot might have been easier to recreate compared to a Cranequn, but uhh props to Shizuko for knowing how to make a Cranequin...and a slap on my face because I'll assume there's no time for mangakas to do in-depth research in crossbow varieties
P.S:
Also Cranequin Crossbows by virtue of the Cranequin usually don't have a stirrup, the loop at the front of the bow at least according to the internet)
Anyways, just a fun fact from another one of my short info-dives.