Medieval Japan typically refers to the Sengoku period (1470-1570ish). Before the Sengoku period, most fighting was done by horse mounted archers. As you can imagine, both skills needed to do this (horse riding and archery) are things that require a great deal of training to do properly. So most soldiers before 1470 were professionals.

However, around 1470 the various lords of Japan, called Daimyo, began switching over to massed infantry armed with pikes after they were shown to be very effective in battle. So most fighting done during the Sengoku era was done with pikes, bows and guns. Swords were a status symbol and side arm. Professional warriors (a very fluid status during this period) carried swords into battle as side arms.

Massed infantry (called Ashigaru) would also sometimes carry swords as side arms, but that mostly depended on how much money a particular Daimyo was willing to spend to outfit them. Swords were hardly, if ever, used as a primary weapon.

Perhaps you should take a look at this thread. Here is another. In fact, the topic of how often swords were used has been covered numerous times.

I don't say any of this to be mean. It's just that this topic is one of the more common on /r/askhistorians. It's an interesting one, and the answers given are usually something along the lines of, "not anywhere near as much as the movies would have you believe."