After receive a few feedback of PSP 1.00 Japan user, about having problem with MPH FL 1.3.7 . So I decide to help again.
MPH Firmware launcher for PSP Japan 1.00 and of course Firmware 1.50 as well.
Version : 1.3.7u5u1 (Last version)
Author : MPH
Patch by : miemt11
1: Support PSP user with Japan Firmware 1.00 (Not tested)
2: Further reduce the eboot size to 40+KB only
3: Last version (I hope) ;)
Update: I forget to include the mphfl.inf file