Combat-Wombat, truly, avoid the double-edged knife in Cali. A single-edged will do plenty, if not more. Just so you know, here's what you can expect if caught with an "illegal" knife in Cali. like a butterfly or "dirk or dagger":
First, they will arrest you. You will go to a holding cell and sit for a couple hours while they get ready to inprocess you. You will be fingerprinted and get a mug shot taken. Then they will fill out a detailed description of you. Then since you're a minor, they'll call your folks to pick you up and you'll be issued a citation for a misdemeanor. Looks just like a ticket you get for a traffic violation (it's out of the same pad.) You will lose the knife. After that, you get to play musical courtrooms where you show up and they reschedule your hearing again and again. Then, your whiz of a public defender will tell you to plead nolo contendre. At that point, the judge will slap you with a $400 fine for carrying that knife and sentence you to a year's probation. If you violate the probation, you get to spend some time in county jail. All this over a knife.
Do yourself a favor. Get a CRKT M16-04Z "Big Dog" tanto-blade folder. You can zip that thing open so fast, your eyes will bug out. And it's easy to keep sharp. Blade is 4" long. And it's legal.