Bokuto (Doctor's Sword or Tea Sword) a kind of oversized sashi netsuke or sagemono that could be used as a club, a status symbol for people like doctors who couldn't wear swords (only samurai could wear swords) or for situations where a sword couldn't be worn.
See also:
Marks
Daruma Issue 7 Summer 1995 Article "Bokuto ('Doctor's Swords') - The Karol Ashken Collection"