Before moving to the Japanese countryside, my experiences of gardening were all in the desert, so learning to grow food in Japan has been a long learning period. One of the main differences between gardening in Arizona and in Japan is that there are few animals and bugs in the desert. Here in Japan it is a constant battle defending the garden against critters. I don't mind sharing,.... I expect to lose a certain percentage of a crop to other critters, but there are some greedy critters.
Caterpillars of the white butterfly (called Cabbage White in England) will consume all the brassica family, cabbages, cauliflower, brussel sprouts etc. Most Japanese gardeners will use pesticide, but for me growing brassicas under net works perfectly.
The only other bug that is a real problem is a little orange bugger that feeds on the leaves of squash plants. Pumpkins will usually recover, but every year my Zuccini plants have been completely eaten and killed by the orange bugs. Every version of organic pesticide I've tried has been completely useless, so I now grow zuccini under net also.
My village garden now has a metal fence around it. The village put it up recently around the rice paddies, and my garden is in the same piece of land as the paddies. The purpose of the fence is to keep wild boars out. Not sure how much damage boars do to rice paddies, but if they get into a garden they will dig up and eat all the sweet potatoes and as many pumpkins they can find.
Down in the riverside garden the ripening corn needs a net to protect it from the crows. They will sometimes eat tomatoes, peas, and other veggies, but they really love newly ripened corn.
The blue fence is to protect against a creature I never knew existed in Japan, the Coypu, or Nutria, sometimes known as Beaver Rat. It is originally from South America, but has spread around the world as people raised them for their fur. It likes to eat cornstalk.
In the bamboo grove next to the garden is a foxes den, and people say the foxes damage the gaedens when they dig around for food, but they have never given me any trouble.
Both gardens have moles, but again they have not caused enough trouble to worry about.
Both my gardens are too far from the edge of the forest for the monkeys to raid, but my neighbors are constantly losing food to them. They particularly like daikons and onions.