Ghost in the Shell: Stand Alone Complex Tips

Unlock Various Dual Handguns
If you start a mission with only a handgun equipped, at the end of the mission you will be rewarded with that same handgun in its dual form - 2 of the same gun that can be equipped at once, only needing 1 weapon slot to hold.
You can use this method to unlock a dual version of each of the standard handguns in the game.