The purpose of this activity is to practice passive grammar through a three-hint guessing game. It's best if the students have had some practice or instruction already.
I start out by coming up with a three-hint quiz for the class to get them used to the idea of the activity. Something like "It's made of cabbage (hakusai). It's eaten in Korea. It's spicy." "Is it kimchi?"
Next I pass out the paper to the students (the file named "play sheet"). I give them all one card from the card sets (the file name "game cards"). Tell them to keep the card a secret - they can't show their classmates or say which card they received. The students have to read their card and write one more hint. If you think they're capable, you can require that the hint use the passive form, but if it might be too challenging, you can let them write whatever they like.
Once the students have finished writing, they should talk to different partners and give their three hints. The other student guesses with "Is it ____?" and once they've guessed the correct one, write their partner's name under the appropriate square in the play sheet. See if they can find people with all twelve cards!
In my classes, I put myself in as one of the hints. I replaced it with Hayashi Osamu for the version I'm uploading here, but I don't know how long he'll be relevant to junior high school students, so I'd encourage you to put yourself or another teacher at the school in his place, as the students usually find that more interesting. The point of the game isn't to be challenging, just to show a bunch of examples of explaining people and things using passive grammar.
If you're doing this somewhere besides Japan then you may need to replace a lot of the items, but the concept can remain the same. If you don't know what "basashi" is, it's sashimi made from raw horse meat. It's eaten here in Nagano but I don't know how common it is in other parts of Japan.