Room 3 is dedicated to weapons. Firearms, displayed in showcase with command fans and metal war hats, came to Japan at the half of the XVI century with Portuguese exchanges. Firearms were called tanegashima like an island in the south of Kyūshū, domain of Tanegashima Tokitaka. With the exception of harquebuses, the techniques then used to produce firearms in Japan were no different from those used in Europe, though there were obviously differences in decorative details.

In showcase 2 and 3 there are swords and daggers without handle: you can see the tang (nagako) signed from the swordsmith and the hole used to insert the bamboo pin to fasten the handle. Japanese sword is a curved single edge blade. In the showcase there are katana blade, more than two shaku long (1 shaku=30 cm nearly) and wakizashi, short swords, one to two shaku long, produced from the XV to the XVIII century.

In showcase 4 there are votive arrowheads: some of them are very simple dovetail, others are finely decorated with araldic openwork motifs. Arrowheads were made as votive offering to Shinto shrines or Buddhist temples.