For a start, have a look at
http://www.eslcafe.com, which apart from useful information about employers (nudge) has a lot of good ideas from practicing ESL teachers.
For Usagi-specific lessons (assuming the NOTHING you do will have ANY copyright implications-- we know Sakai-sensei is mild and nice, but he's not entirely in charge of the legal end of things):
CLOZE exercise: Students in pairs, each with a page of the book; each partner has the same page, but with different words blanked out in alternating balloons. They take turns reading (vocabulary recognition, pronunciation) while the partner fills in the blanks in their paper (writing using Roman characters, understanding spoken language, spelling). When they're done, they can read back what they wrote to see if it makes sense, or just look at each other's paper (time pressure). Depending on the vocabulary, good for intermediate or
very high beginners.
Alternative CLOZE: If you want to talk more, or give the students more practice hearing a native speaker, give them each a page with slightly different blacks, then read yourself from a master. When done, get each student to read back from theirs by way of correction, and to give them practice speaking. Same level as previous, although slightly more attainable for the low-level student.
Creative writing: Students each get a page (or panel) with all the dialogue removed. They have to make some up, and depending on your focus, just write it out, or read it to the entire class (for this and the previous item, if the class has an overhead projector so everyone can see the page at once, all the better). This is a fairly advanced project-- high-intermediate at very least.
Vocabulary builder: For the beginners. Get some pictures of the main characters. "This is Miyamoto. He is a Rabbit." (If you're in Japan, "Usagi" is a bit of a give-away

) Go through three or four of them, then start with the questions; "Who it this?" -> "That is Gen." Make sure the responses are more than one word-- if it isn't Subject-Verb-Object, they have to go again.
That's all I've got off the top of my head. I'll try to give it some more thought before too much time passes.
"...[H]uman beings are given free will in order to choose between insanity on the one hand and lunacy on the other..."
Aldous Huxley, 1946