i tried playing with cheats and couldnt increasse the main characters energy no matter what i did, so a bunch of scenes were locked out to me.

i maxed out every scene that i had access to, but it didnt increasse my energy at all.

 leveled up kuina and myself a lot too, but that also made no diference.

I recommend you play the game and read the tutorials, it would make more sense to you.

Player Energy is based on your Vitality stat, if you increase it, the maximum energy will increase aswell.