My mail box is already flooded with mails from TOEIC people telling me to take other tests they offer. They have TOEIC SW (Speaking & Writing) as well as something called TOEIC LPI (Language Proficiency Interview).
Getting back to the topic of teaching TOEIC, my husband and I went out for dinner last night and passed by a pretty respectable English conversation school (not one of the big chains) in our neighborhood. I had been talking about this thread with him, and he decided that he wanted to check the school out.
He went there, claiming he dropped by to ask for info for his kids (!!) and asked about TOEIC and TOEFL. The lady owner there was very helpful (who isn't?) and told him about the courses the school offers for college students and adults.
As I mentioned earlier, it seems that getting high scores (not talking about you ASHIKAGA but Japanese learners of English in general) have become easier with help of schools like this, especially because the main TOEIC test is multiple choice format. That is why TOEIC now has the S/W (Speaking/Writing) and LPI (personal interview) tests, as well as TOEIC Bridge for younger people (junior high/high school level). These tests reveal the person's true English ability and are becoming important.
TOEFL has also added essay writing as a requirement.
I don't think ASHIKAGA needs to take these tests, but study into these tests will be important in teaching. You need to teach how to make short speeches, write essays, and state opinions on common topics.
For the same reason, Eiken has become important because the first part of the test includes a writing test, and the second part (held on a separate date) requires you to make a short speech in front of the other test-takers and native-speaking STEP representatives.
I think your next step is Eiken Grade 1. It's a breeze in your case, so ganbattene!

FYI, Eiken Grade 1 notifies you whether or not you passed the first part of the test. If you pass the second (speaking) part, they give you your "hensachi" score, which is very much like that "hensachi" you get in testing for university admission.