The following are known CWCheat Codes for Boku no Natsuyasumi 4: Seitouchi Shounen Tanteidan, Boku to Himitsu no Chizu on Sony Playstation Portable (PSP).

_S UCJS-10095
_G Boku no Natsuyasumi 4: Seitouchi Shounen Tanteidan, Boku to Himitsu no Chizu [JP]
_C0 50 GAME CREDIT 5
_L 0x0140A4CA 0x00000005
_L 0x0140A60C 0x00000005
_L 0x0141B823 0x00000005
_L 0x0141B8B6 0x00000005
_L 0x0141B8BB 0x00000005
_L 0x0142BB6B 0x00000005
_L 0x0142BB6D 0x00000005
_L 0x0142BB6F 0x00000005
_L 0x0142BB75 0x00000005
_C0 00:00 PM
_L 0x002BF91D 0x0000000C
_L 0x002BF91E 0x00000000
_C0 01:00 PM
_L 0x002BF91D 0x0000000D
_L 0x002BF91E 0x00000000
_C0 02:00 PM
_L 0x002BF91D 0x0000000E
_L 0x002BF91E 0x00000000
_C0 03:00 PM
_L 0x002BF91D 0x0000000F
_L 0x002BF91E 0x00000000
_C0 04:00 PM
_L 0x002BF91D 0x00000010
_L 0x002BF91E 0x00000000
_C0 05:00 PM
_L 0x002BF91D 0x00000011
_L 0x002BF91E 0x00000000
_C0 06:00 PM
_L 0x002BF91D 0x00000012
_L 0x002BF91E 0x00000000
_C0 07:00 PM
_L 0x002BF91D 0x00000013
_L 0x002BF91E 0x00000000 
_C0 08:00 AM
_L 0x002BF91D 0x00000008
_L 0x002BF91E 0x00000000
_C0 08:00 PM
_L 0x002BF91D 0x00000014
_L 0x002BF91E 0x00000000
_C0 09:00 AM
_L 0x002BF91D 0x00000009
_L 0x002BF91E 0x00000000
_C0 09:00 PM
_L 0x002BF91D 0x00000015
_L 0x002BF91E 0x00000000
_C0 10:00 AM
_L 0x002BF91D 0x0000000A
_L 0x002BF91E 0x00000000
_C0 10:00 PM
_L 0x002BF91D 0x00000016
_L 0x002BF91E 0x00000000
_C0 11:00 AM
_L 0x002BF91D 0x0000000B
_L 0x002BF91E 0x00000000
_C0 11:00 PM
_L 0x002BF91D 0x00000017
_L 0x002BF91E 0x00000000
_C0 8/1
_L 0x00969B5C 0x00000001
_C0 8/10
_L 0x00969B5C 0x0000000A
_C0 8/11
_L 0x00969B5C 0x0000000B
_C0 8/12
_L 0x00969B5C 0x0000000C
_C0 8/13
_L 0x00969B5C 0x0000000D
_C0 8/14
_L 0x00969B5C 0x0000000E
_C0 8/15
_L 0x00969B5C 0x0000000F
_C0 8/16
_L 0x00969B5C 0x00000010
_C0 8/17
_L 0x00969B5C 0x00000011
_C0 8/18
_L 0x00969B5C 0x00000012
_C0 8/19
_L 0x00969B5C 0x00000013
_C0 8/2
_L 0x00969B5C 0x00000002
_C0 8/20
_L 0x00969B5C 0x00000014
_C0 8/21
_L 0x00969B5C 0x00000015
_C0 8/22
_L 0x00969B5C 0x00000016
_C0 8/23
_L 0x00969B5C 0x00000017
_C0 8/24
_L 0x00969B5C 0x00000018
_C0 8/25
_L 0x00969B5C 0x00000019
_C0 8/26
_L 0x00969B5C 0x0000001A
_C0 8/27
_L 0x00969B5C 0x0000001B
_C0 8/28
_L 0x00969B5C 0x0000001C
_C0 8/29
_L 0x00969B5C 0x0000001D
_C0 8/3
_L 0x00969B5C 0x00000003
_C0 8/30
_L 0x00969B5C 0x0000001E
_C0 8/31
_L 0x00969B5C 0x0000001F
_C0 8/4
_L 0x00969B5C 0x00000004
_C0 8/5
_L 0x00969B5C 0x00000005
_C0 8/6
_L 0x00969B5C 0x00000006
_C0 8/7
_L 0x00969B5C 0x00000007
_C0 8/8
_L 0x00969B5C 0x00000008
_C0 8/9
_L 0x00969B5C 0x00000009
_C0 BOKU METER MAX 
_L 0x20969B74 0x41400000 
_C0 BREATH GAUGE MAX 
_L 0x20760174 0x4140000
_C0 EMPTY BOTTLE
_L 0x20969BBC 0x00000BB8
_C0 FISHING
_L 0x20969BAC 0x0000001E
_C0 GAME HIGH SCORE
_L 0x20969BC4 0x0000C350
_C0 INSECT COLLECTING
_L 0x20969BA8 0x00000096
_C0 Maney 9999
_L 0x20969B78 0x0000270F 
_C0 MONKESHI
_L 0x20969BB0 0x0000001E
_C0 PICTURE DIARY
_L 0x20969BA4 0x000000AA
_C0 SUN TAN
_L 0x20969BC0 0x00000007
_C0 Taiko de Tatsujin
_L 0x2073FD50 0x00000064
_C0 TEST WORD
_L 0x20969BB8 0x0000001A
_C0 VERMING SUMO
_L 0x20969BB4 0x00020001