Etymology: An old form of this character shows the base horizontal stroke as tree roots. Many meanings have evolved from this, usually pertaining to essence/origin. This character is also used for counting cylindrical items.
Mnemonic: TREE WITH ONE CENTRAL ROOT
日本 (nihon/nippon) Japan
本屋 (honya) bookstore
本店 (honten) head office / this store
(Based upon Henshall, 1998)