Mission select:
Complete the arcade mission mode to get mission select in arcade mission and another mission modes.

Chat mode:
Choose Combat School and quickly press Square during loading until you see
the menu. The instructor asks you to chat with her.

Combat School rankings:
Rank Points
Super Devil 1000+
General Of Army 990+
Lieutenant General 890+
Major General 780+
Brigadier General 700+
Colonel 650+
Lieutenant Colonel 600+
Major 575+
Captain 560+
1st Lieutenant 550+
2nd Lieutenant 500+
Chief Warrant Officer 475+
Warrant Officer 450+
Sergeant Major 425+
Master Sergeant 400+
Sergeant 1st Class 350+
Staff Sergeant 300+
Sergeant 250+
Corporal 200+
Private 1st Class 150+
Private 100+