Meaning
Half moon
Also known as Seisan/Seishan meaning 13.
History
The lore of several Shorin-ryu factions has it that the Shurite Seisan had been practiced in Okinawa for about 200 years. The form used in most Shorin-ryu derived systems was supposedly developed originally by Matsumura. Funakoshi simplified the variation he learned from Itosu and Azato and called it Hangetsu.