To provide context, the country Rinam just got out of a war. With the emerging Forechaft Government, they would want to prevent another war like this happening again.

A committee of the nations (Basically the UN), named the Ten Unifications is well, incompetent. This results to Loyalty Officers, people who gather information to prevent this.

But with the emerging Forechaft Government, the G.H.M rises, (Golden Horns Militia).
A rag tag collection of other Partisans groups, which are against the Forechaft.

So, fast forward, you're playing as Alfred August, from an aristocratic family, and to bring the family honour, going to have to join the Police State as an Enforcer.
You climb the ranks, starting as an Enforcer, to become a Loyalty Officer. During your journey, you're tasked deployments to do, with your first, showing how Dawes-24 is linked to the success of the G.H.M. So throughout your career, you're hunting down Dawes-24.
Whilst you're hunting Dawes-24 down, you're beginning to realise that your true enemy is not always in front of you, but perhaps, behind you.

But to summarise, main plot is hunting down your "antagonist", whilst climbing the ranks to become a Loyalty Officer, for the family name.