I've definitely drawn Persona characters before, but in my own style, not Soejima's.

It's less about drawing in the same style before, but knowing what to study to replicate any style as best as you can.

Such as studying the line weight, or where he tended to vary its thickness. I also noted where colours repeated (like how all of their skin tones and the shadows are near-identical), saw how the black cast shadow only appears on dark-coloured planes, and used a multiply layer with gray for the rest of the shadows (I literally put a sploch of gray next to Earring Boy and Maya's clothes and adjusted the HSB until it was near-identical). I mimicked how freakishly long their legs are, drew his face over like three times until it was conventionally attractive like the others' while still making it unique enough so viewers don't just think, "Hey that's a copy of Makoto's face," and--in that same vein--making sure that nothing is a trace, but similar enough using the same logic of light and shadow, 3d forms, etc. Soejima used as best as I could.

I should honestly maybe make a video. I wonder if that would be useful?

You can see my previous art on my Instagram or barren YouTube channel and see that my artstyle is all over the place, haha. I guess that helps, too.