http://legislature.mi.gov/doc.aspx?mcl-750-224
Section 750.224
(1) A person shall not manufacture, sell, offer for sale, or possess any of the following:
(d) A blackjack, slungshot, billy, metallic knuckles, sand club, sand bag, or bludgeon.
(2) A person who violates subsection (1) is guilty of a felony, punishable by imprisonment for not more than 5 years, or a fine of not more than $2,500.00, or both.
Not a lawyer or LEO, but for whatever it's worth that doesn't sound kubotan-friendly to me.
http://legislature.mi.gov/doc.aspx?mcl-750-226
Section 750.226.
(1) A person shall not, with intent to use the same unlawfully against the person of another, go armed with a pistol or other firearm, or a pneumatic gun, dagger, dirk, razor, stiletto, or knife having a blade over 3 inches in length, or any other dangerous or deadly weapon or instrument.
(2) A person who violates this section is guilty of a felony punishable by imprisonment for not more than 5 years or a fine of not more than $2,500.00.
"Any other" makes it a judgement call, and who needs a felony arrest?