The
Japanese term for
vertical writing.
The typical direction of writing used in many books, including manga.
When you read a book written in tategaki, you begin by turning to what would in an English-language book be the last page. You then read down the columns of characters in order, starting with the column on the right.
This right-to-left tendency of tategaki is why translations of manga into English often flop the pictures.
Compare yokogaki.