Preheat your oven to 250º F. Then, mix the cereal and pretzels together in a large bowl or large pot, and set it aside.
Add the butter, corn syrup, vegetable oil, sugar and soy sauce to a small pot over medium heat. Stir the mixture occasionally, and remove it from the heat once it comes to a simmer.
Pour the sauce over the cereal mixture and gently mix it until evenly coated. Then, pour the entire bottle of furikake over the cereal, and mix it again until the furikake is evenly distributed.
Divide the cereal mixture evenly between two large sheet pans. Then bake in the oven for 45 minutes – 1 hour, stirring every 15 minutes to make sure it’s cooking evenly. You’ll know it’s done when the sauce has dried out and the cereal is crunchy.
Let it cool completely, and store in an airtight container or bag. Enjoy!