It is often incorrectly claimed that the samurai found firearms to be dishonourable, but being warriors, any weapon that gave them an advantage was quickly adopted into the samurai arsenal. The foreign imported matchlock gun was no exception, and once the problem of forging the important breech screws closing the rear of the steel tube was solved, the Japanese were churning out guns by the thousands.
Like the rich of today, the samurai enjoyed their novelty items such as flamboyant helmets and unusual, creative articles, hence the creation of this rare repeat firing gun box set —basically an early Edo period machine gun. These two cabinets were the property of Lord Tokugawa Mitsutomo (1625-1700), the second Lord of Owari Domain, based in Nagoya Castle.
Each cabinet stands approximately 55cm high and 40cm wide. The twin doored cabinets contain four drawers each. The top three draws bear five mounted miniature cannon-like gun barrels lined up perfectly with small holes in the back of the drawers that correspond with an equal number of holes in the back of each cabinet itself, making for 15 guns per box, and a set of 30 guns in all. The lower, slightly deeper fourth drawer contained cleaning and maintenance tools and accessories.

Forged by the famed gunsmithing community of Kunitomo Village in Omi, modern day Shiga Prefecture, the bores were 1.4 centimeters in diameter and each hexagonal barrel was about 32cm long. Like most matchlock guns, they were single shot, front loading firearms.
According to notes, the sets were difficult to construct, and equally difficult to prepare for firing. Set facing the enemy, the front doors of the cabinets could be opened to reveal the drawers containing the pre-loaded firearms. A small hole in each drawer front allowed for the match to be inserted, igniting a tiny amount of fine gunpowder carried in a small indent and hole at the top of each tiny cannon. This would ignite the black powder in the rammed into the breech and the guns would fire the lead shot through the holes in the back of the drawer and cabinet.
As for use, being matchlocks, the guns in the drawers fired almost simultaneously. No doubt cleaning and maintaining such a set would also be a difficult task, however, not to worry, as Lord Mitsutomo had over 7,000 samurai garrisoned at Nagoya Castle alone to do the cleaning for him. These cabinets and guns remain the property of the fascinating Tokugawa Art Museum, housing the worlds’ largest collection of daimyo armour and weapons, personal items, scrolls, tea ceremony implements, Noh costumes, masks and more. This gun cabinet is rarely displayed, and has probably never been fired since a few test shoots in the early Edo days. There are no known records indicating their range, accuracy or effectiveness, and the way they are set suggests they were to be used in a shotgun like manner, possibly fired towards groups of enemy. Despite their small size, the cabinet mounted guns would have created quite a noise and may well have literally been the boom-boxes of the samurai.
From where exactly this idea of "samurai dont use guns" comes from? Because absolutely all source material, all museums, all japanese historical movies/tv drama show its importance.
Its from the Last Samurai? I feel a little guilty because, even knowing how bad this movie is, was one of the mais reasons for my introduction in the japanese history.