As long as the knife doesn't look scary, you may be ok. Unfortunately, like the majority of Hawaii laws, the "dirk" description gives the prosecutor too much discretion on who is legal and not legal. In California, several years back, some judge somewhere ruled that the Spyderco Mariner is, in fact, a "dirk" by their standards.
It is funny that that quoted red text cites a butterfly knife as both a dangerous weapon, and not a dangerous weapon. I believe it is not a dangerous weapon, but it is prohibited under its own specific "possession of a butterfly knife" statute