The foodFlea markets are great places to find street food, and Japanese street food is some of the world's best. There is no need to worry about sanitation (I never fell sick even though I ate street food everywhere) and you can go all out as prices are really reasonable.
Other than the usual Takoyaki and Taiyaki stuff, the flea market also sells roasted chestnuts and dried seasonal fruits, so when I visited there were persimmons everywhere.
The clothes If you plan to buy a Kimono as a souvenir, this is the place to buy it. Kimonos and yukatas are sold for as low as 500 yen, and both new and second hand options are available.
Textiles and fabrics are also sold in some of these stalls. If you want something smaller, pouches and bags with traditional Japanese designs and cloth are also sold.
The pottery and laquerware Pottery is literally everywhere in this market. The pretty designs are really attractive and some of the pottery is hand made! You will find everything from clay bows to ceramic vases. There are wooden chopsticks with traditional designs and ceramic showpieces. Just remember to wrap these properly in your suitcase!
The antiques The coolest items sold at these flea markets are definitely the antiques, which can range from kettles to samurai helmets. The antiques usually have the most variety and sometimes you can find beautiful hidden gems at reasonable prices. Even if you aren't buying anything, these pieces are really interesting and will catch your eye.
The hand made knick-knacks and jewellery Most of the jewellery you will find at the flea markets are hand made items, and range from hair ornaments to rings. For those familiar with the Buddhist beads, they are also often sold alongside statues of the Buddha.
You can find other really random items including wind chimes, wooden dolls, key chains and good luck charms. When I visited, there was a lady selling key chains resembling the many cats she had rescued.
The weird Sometimes there are just really bizarre things being sold, like these vintage baby dolls. Sometimes even normal cultural icons such as Tanuki and Tengu can look strange to our foreign eyes, so looking around the flea market really gives a sort of 'only in Japan' vibe.
Temple flea markets are a really fun experience and Toji temple has one of the best markets in Kyoto. So if you're in Kyoto around the 21st of the month, do include Toji temple in your itinerary!