The Happy Wars campaign is not like many campaigns as it is played in story segments, or chapters. You will need to achieve a rank online to proceed through the story mode. Every 5 ranks you unlock a story mode chapter. There are 6 story mode chapters and each contains 1-3 missions. Like in Multiplayer mode, the battles are fought between the Light and Dark forces.
Chapter 1 First sortie of the Knights
Chapter 2 Debacle of the century!
Chapter 3 Chasing princess...
Chapter 4 Spirited Away in the Desert Village
Chapter 5 Happy of the Dead
Chapter 6 War! The Kingdom of Dark!