Japanese IO uses the JMdict, JMnedict and Kanjidic2 dictionary files, which are the property of the Electronic Dictionary Research and Development Group and used in conformance with their licence.
JLPT level information is from Jonathan Waller's Japanese Language Proficiency Test Resources page.
Texts in the classics section in the public domain from Aozora Bunko. Author and text metadata (作家別作品一覧拡充版) is unmodified from Aozora Bunko and used under a Creative Commons (CC BY 2.1 JP) license. Author and text descriptions/excerpts are from Wikipedia and used under a Creative Commons (CC BY-SA 3.0) license. Author images are from Wikipedia and in the public domain or used according to the license indicated.
The picture of a bamboo grove, used as a background on the landing page, is in the public domain and can be found in the Wikimedia Commons.
Japanese IO is copyright © 2019 by Atilika Inc. All rights reserved.