There's no better way to say, "Good luck on your school exams," than with citrus fruit pentagons, am I right?
Fruit farmers in Ehime Prefecture, Japan have created "Gokakukei Iyokan" (五角形イヨカン). A mix of mandarians and oranges, "iyokan" is sometimes called a "Japanese Summer Orange." And in Japanese, "gokakukei" (五角形) means "pentagon." But this special fruit's name is a pun!
See, "goukaku" (合格) means "successfully passing an exam." And "ii yokan" (いい予感) means a "good premonition." So, if written like "goukaku ii yokan" (合格いい予感), it means "to have a good premonition of exam success." Clever!