With a few exceptions like carrying on school grounds, into airports or government buildings, carrying switchblades/butterfly knives, belt buckle knives, and a few other obscure references, California state law has no restrictions on the size of knife one can carry in public. Under state law there is no size or blade length limit on folders carried openly or concealed, or fixed-blades carried openly.
However some cities/counties have their own length limits and restrictions. For example, Los Angeles city and county have a 3" limit on the length of blade that can be carried openly (both folders and fixed), but no length limit on folders carried concealed. There are exceptions to their length limit on openly carried knives, like carrying a knife for "legitimate" work or "recreational" purposes, etc.
There is nothing about the size or design of the Manix or Manix 2 that would make it illegal under CA state law to carry off school property.