Japan has always been a warrior culture, so as the Bagpipe Airship descends, signalling the start of the Scottish invasion, defenders are already preparing for war. The first of these defenders that the Scotsmen encounter are the Rice Farmer and the Sumo Wrestler.
The rice farmer is the most common Japanese enemy, specialising in ranged combat. Their fighting style is similar to that of Scotsmen, only instead of throwing bowls of porridge, they throw balls of rice. This along with their decent speed makes them a good all-rounder, able to take on many different types of towers. They can be especially difficult if allowed to use cover. The best way to defeat them is to hold them at bay with barricades, which provide excellent protection from their attacks, while hitting them with longer ranged towers.
Sumo wrestlers are the polar opposite of rice farmers, being incredibly slow and difficult to kill, and lacking any ranged combat abilities. Unlike other melee enemies, they don't have to attack to cause damage, they simply squash any Scotsman or tower that they touch. This makes them one-hit-killers, especially devastating if they reach any of your hero characters or expensive towers. This also means that they can only be attacked using ranged weapons. Fortunately their slowness makes it easy to kill them before they reach you, as long as you have sufficient fire-power. Their main strength is that they take a lot of hits to kill, so they can draw a lot of fire away from other enemies who can use this opportunity to attack more easily.