https://www.mangaupdates.com/showtopic.php?tid=12065 - Here's a link to a Baka-Update forum post all about vaguely educational manga. Almost all of the manga is fictional, but they supply lots of information about historical events, cooking/food, Japanese life/history, and more!

http://www.mangashakespeare.com/ - This series takes actual lines from Shakespeare's plays and illustrates them in crazy settings! Haha! Several of them are futuristic and couple are Victorian-ish, but they are pretty entertaining.

http://www.howtodrawmanga.com/ - Manga University is a publishing house famous for the "How To Draw Manga" series, but they also have published a cookbook and several books covering kana and kanji!