Boring Healthy Cereal Post

Hey Y'all. Doctor's orders. I gotta stick to Bran Flakes and All Bran. Basically lower sugar, higher fibre stuff. But for the life of me I can't find any actually healthy cereals or granolas in the stores (or on Amazon) in Japan. Even the stuff marketed as health conscious is like 5-10g of fibre to 25-35g of sugar per serving.

I'm sure most of the replies will be along the lines of 'this is Japan, it's not a cereal country etc' but if anyone has any advice on getting actual healthy cereals here (in store or online) I'd very much appreciate it.