Not that it's really matters, but just for fun I will post thematic explanation suggestion for the left side of the samurai cards.
Some of the villagers decided to help you in the battle, so each one of you get 3 sidekicks.
In the heat of the battle there are a lot of attacks on the families/houses. Instead of fighting you able to let one of your sidekick to handle some of the enemies. Meanwhile you can rest, save house or save family.