After I missed the only trigger to start the social link for Yuko in Persona 3 FES I found a cheat to start the social link nonetheless:
// Press L1+L2 to set social link rank with Yuko to 3
patch=1,EE,D07E0842,extended,0000FAFF
patch=1,EE,00836280,extended,00000003
The problem is that the...