Translated from the Japanese.
Translators vary between volumes.
Reads from right to left, reads from back to front.
"First published in 2003 by Media Works Inc., Tokyo, Japan"--Vol. 1, colophon.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Yotsuba&! by Kiyohiko Azuma. ISBN 9780316190336. Published by Yen Press in 2009. Publication and catalogue information, links to buy online and reader comments.
