(updated in response to a request for pictures)
Some English conversation schools for kids have full-on Halloween parties, large affairs with the participants in elaborate costumes. Me, I run a fake English school in which half the student population of two shares a good deal of DNA sequence with me. So it seemed fitting to have a half-assed Halloween party (but not until we went through the 18 alphabet flashcards and 30 vocabulary flashcards first). I bought some individually wrapped candy and cookies at the local supermarket, and witches' hats and Halloween decorations at the 100 yen store.