DRAGON QUEST HEROES II is a hack and slash-based action RPG set in an open landscape. Players embark on adventures to restore order to what was once a peaceful world, but now is a wasteland filled with monsters and magnificent battles. Up to four players can collaborate in multiplayer to fight waves of enemies and defeat challenging boss monsters. There are a variety of playable characters to choose from, including a range of familiar faces from, the DRAGON QUEST® series and four new heroes. They all have unique special attacks and abilities and must work together to take up the fight against a mysterious enemy that threatens the seven kingdoms.

Once upon a time, a protracted and cruel war was fought. When the war finally ended, the people of the world made a solemn pact never to fight each other again. The world was divided into seven kingdoms, and peace reigned for a thousand years.

One day, the two relatives and knight apprentices Lazarel and Teresa are reunited in the Kingdom of Harba - far from their Dunnis hometown. They have no idea that Harba is being invaded by the Dunis army, which has their old friend Prince Cesar as army commander.

The long-lasting peace is abruptly broken and the world is thrown into chaos. With the help of the High Kings envoy, the two relatives must travel to Accordia and meet the overlord of the seven kingdoms to find a solution on how peace can be restored in the world!