Shinto shrines tend to have a large number of small shrines like this one (Imamiyajinja has about 20, I think). They are constructed in the same general shape as the larger shrines (note the bell rope and offering box). I have no idea why there are so many. I assume there are either many kami whose aid might be worth receiving, or that some of the shrines are personal shrines to the same kami as the main shrine by particularly devoted followers.