Iyo Kasuri Folk Craft Museum focuses on the indigo-dyed kasuri textile tradition associated with the Matsuyama area. It is a small craft museum, but it gives useful context for a local product that can otherwise appear only as a souvenir.
Go if you are interested in textiles, folk craft, or regional design. The museum is best treated as a short stop and paired with other Matsuyama sights rather than a main destination.