You must be Oda Nobunaga for these codes to work:
3EF-9FB-191 Train samurais once and they have 100 % skill level
4B1-5AA-2A2 Start with 75 loyalty pts.
641-5AA-2A2 Start with 100 loyalty pts.
321-56A-80E Start with 50 town value pts.
4B1-56A-80E Start with 75 town value pts.
641-56A-80E Start with 100 town value pts.
321-5CA-D56 Start with 50 castle defense pts.
4B1-5CA-D56 Start with 75 castle defense pts.
641-5CA-D56 Start with 100 castle defense pts.
4B1-5BA-2A2 Start with flood control level at 75
641-5BA-2A2 Start with flood control level at 100
0AE-B6B-B3A + 0AE-B9B-E6A Start with 2580 rice pts.
03E-B6B-B3A + 03E-B9B-E6A Start with 788 rice pts.
01E-B6B-B3A + 01E-B9B-E6A Start with 276 rice pts.
0AE-B6B-D56 + 0AE-B7B-E6A Start with 999 gold
3E5-7EA-191 Attributes for Oda Nobunaga are 100% (will show original 
values, answer no when asked if this is OK--then attributes will be 100%)