A1: Hold and press L1+L2+R1+R2 down right2x press down L3&R3 together

A2: You can use the cheat:
1.Hold R1 & R2 Press square,triangle,square,triangle
2.Hold L1 & L2 Then press >,^,>,^
3.Press L3 & R3
4.You should hear a sound
Hope this works,and the other 2 characters??
Just date Hanabi Hyuuga

A3: When your on the main menu hold r1 and r2 at the same time then press square,triangle,square,triangle then switch to holding l1 and l2 at the same time and press right,left,right,left then stop and press l3 and r3 at the same time you will hear a sound confirming the password

A4: You can use a cheat code on the menu screen: hold R1+R2 then square, triangle, square, triange. Hold L1+L2 and then right, up, right, up, and finally hit L3 and R3 at the same. It'll make a jingle if you did it right. After that, you'd have to go on a date with Hanabi (there are walkthroughs for this) and then you've unlocked them all. If you would rather do more work for each character, go to gamefaq or google a NH3 walkthrough, they have different ways to get each character. good luck~

A5: At the title screen where the guide ninja is you then push the following buttons in order-R1,R2,@ the same time then square triangle square triangle then L1,L2@ the same time then right up right up unlocks all chracters accept (4th hokage) and ( Hinabi Hyuga) I hope that this helps!