largest city: Matsuyama / prefectures: Kagawa, Ehime, Tokushima and Kochi
Kotohira-gu, commonly known as Kompira-san is definitely the most famous shrine not only in Kagawa prefecture, but also entire Shikoku. You need to walk up 785 steps to reach the inner main shrine.
Iya region in Tokushima prefecture is one of the isolated, hidden wonders of Japan. Oboke gorge and Iyakazura bridge(simple suspension bridge) are waiting for you.
There is an island which is offshore of Shikoku and known to foreigners but not to Japanese outside of Shikoku. Naoshima, it is the top destination for art lovers around the globe.
Matsuyama is the prefectural capital of Ehime and the most populous city on Shikoku. Tourists enjoy bathing at Dogo hot spring and Matsuyama castle.