The item shop sells items to villagers while a traveling merchant sells to outlaws. These items include weapons, armor, and healing items. Armor unnoticeably increase defense. Weapons and healing items are usable in battle. The requirement to using them is a minimum rank. To obtain them, you can either purchase them or win them during certain events.
You can buy or sell items at the market. When you click on “Trades”, you'll be brought to a menu. You can browse through items to see if there's something interesting or search for a specific one. You can also put up certain items for trade. To add an item or two for sale, click on New Trade. Here, you can choose whichever item(s) you wish to auction off. When you hit Submit, 500 ryo will be taken out of your pocket for “administrative fees”.
If you've already made an offer on an item, you can check it by clicking My Offers. If you have an item up for auction, you can check its status by clicking on My Trades.