For Tsukasa's hat, I just improvised and it turned out pretty well (I think). One piece of advice, I used gold fabric paint as the trim around the jewels instead of fabric. It may sound cheesy, but the paint gives you more freedom to make the trim how it looks on the character than just a straight line of fabric trimming, in my opinion.
As for the over shirt, I just used a pattern for a hoodie -- Butterick #3255. You might have to adapt it somewhat, as in make the sleeves wider and shorter, and omit a zipper, but it's not too hard to change things like that. Now for the brown accoutrements and trimmings, I'll leave those up to you.
Well, I hope that made sense
. And good luck.