An improvement of @kim123 's@kim123's answer. Using Bc1 instead of Nb1 can getis one move faster. (White's move 9)
1. d3 d6 2. Kd2 Kd7 3. Kc3 Kc6 4. Kb3 Kb6 5. Ka3 Ka6
6. Be3 Be6 7. Bb6 Bb3 8. axb3 axb6 9. Kb4#
(haven't got enough reputation to comment..)
1. d3 d6 2. Kd2 Kd7 3. Kc3 Kc6 4. Kb3 Kb6 5. Ka3 Ka6
6. Be3 Be6 7. Bb6 Bb3 8. axb3 axb6 9. Kb4#