Fukubukuro, bags filled with mystery objects, are usually sold around New Year's, and I always think the surprise is so fun. It's not common, but every once in a while you'll find them at another time of year.
Just last week a new convenience store opened in our neighborhood and to celebrate they were selling lucky bags. I knew they would only be convenience store snacks, but Raku and I still got them just for fun. As suspected, they were just typical conbini junk food but we enjoyed opening them. The green tea was the most practical. The weirdest? Tuna crackers. The best - cinnamon almonds, I would definitely buy those again!