Adachi from Persona 4 joins THUGPRO! credits to ThatTrueStruggle for the model. 

Replace the Model .tex and .skin in C:\Program File (x86)\Activision\Tony Hawk's Underground 2\Game\Data\models\Skater_Secret

add the three skaterparts files in C:\Program File (x86)\Activision\Tony Hawk's Underground 2\Game\Data\Pre
if it askes to replace them, click "Yes"
and you should see adachi in the game.

credits for ThatTrueStruggle on adding the model to model resource
credits for youtubers who helped me on how to add the model in the game :) 

also avaible on THPSX: https://thpsx.com/creation-details/?obj=2052