Yoka Shrine is a holy place where religious souls meet to pray. You can do the same, or respectfully observe others as they worship.
If you're planning to stick around a while in Saga, Yoka Shrine is an interesting place to start your sightseeing. This sacred place is one of many attractions that'll keep you busy here. Saga Castle, Saga Prefectural Government Office, and Saga Prefectural Art Museum are also waiting to be discovered close by.