Hi, I also liked the Assimil for Japanese. Thats how I started Japanese when I was at school about 20 years ago. I like it, because Japanese differs from German a lot. And Assimil focussed also on word by word translation. This helped me a lot. You need to understand haw a language works. Having a book without literal translation will lead you nowhere. What is important is the use of the language. So with japanese the writing and reading is exhausting and thats why I stopped learning it. But I still like to watch japanese drama online. So listening is key and also talking. No children learn their language by reading and writing. So I think this will help your class. They also get moved by using the language and so the ice is broken and hopefully you class will come to more conversation.

for example , if you give 3 lesson per week try to have 2 lesson using Minna Nihongo and 1 free talk lesson (General discussion ,reading a story ) you can read a story to them and see how much they understand. then they can try to read it out loud several. if the story have Dialogue they can act it. I am very bad with following text book , so i use Stories to learn Japanese . and that motivates me to study from the text book every once in a while , when i face a grammar point i don't understand .

I've heard about a teacher who used Heisig's Remembering the Kanji in class and had a great success. It's great, because in about 3 months you can learn how to write and distinguish all kanji required for jlpt n1. But it's an unusual way to teach, so it's really rare to see someone teaching without relying on textbooks a lot. If I ever had to learn Japanese from the beginning again, I would use RTK and then use Assimil series (or Teach yourself series if there is no Assimil one for the language). Assimil is basically 100 lessons/100 dialogues with audio and grammar notes. The point is to listen to dialogues and look at the translation until you can understand them fully, then after 50 lessons you begin translating from English into Japanese the same dialogues, which forces you to produce some input. It's the most used course by polyglots. It won't make you take you to a native level, but you'll be able to communicate after it. Both RTK and Assimil are fun and can take you to low intermediate level in all aspects of a language in a few months. There is some grammar and exercises in them, but they don't rely on them too much. I haven't heard about using Assimil in class though. Good way too, would be to use media, but I don't believe it's possible to find something, that would interest 14 people in a class. I know many people who want to learn Japanese, but either they don't even try or they give up when they have to learn kanji. When people think about learning languages school, boring textbooks and exams come to mind, no wonder there arent that many who do it.