Thread:Sango 珊瑚/@comment-4576906-20150628054543/@comment-25331127-20150701095614

Let me list everything we found in the few past months: Currently I'm not quite sure about what are these about except 犬夜叉 超特別篇: Basically they're bonus episodes in the Japanese (Taiwanese as well, but I'm not certain if VIZ also includes them) DVDs that summarize the story in the corresponding seasons.
 * 犬夜叉 超特別篇 (InuYasha Extremely Special Episodes)
 * 犬夜叉 ひみつ烈伝！！ (InuYasha Secret Biography!!),
 * 犬夜叉 ひみつ＆クイズ百科 (Inuyasha: Secret & Quiz Encyclopedia),
 * 劇場版テレビ版 犬夜叉アニメ全書 (Movie and Television version: InuYasha Anime Complete Set),
 * セイカの ぬりえ 犬夜叉 (InuYasha Coloring Book), and
 * "LINE stickers" as well. :P

The other ones were 吹奏楽のための犬夜叉 (InuYasha Wind Instrumental) (But on the Internet, they call it ""INUYASHA" for Symphonic Band"), which I've created its individual page, and added to the "Official Tracks Unlisted in the InuYasha Discographies" section of the Music page. And 犬夜叉打樂連歌 (InuYasha Percussion Suite), also listed in Music page on top of the section.

Actually it's Sango who found most of the books, so the credit belongs to her. :)