Who, as a pupil, did not dream of drawing a moustache on the Mona Lisa? On seeing a famous figure in a textbook, some pupils just can't resist adding spectacles to the Queen or gangster scars to Buddha.
Some go further, transforming a dull history book into a work of art - particularly in Japan, where generations of Manga-reared scribblers secretly daub over books to the scandal of taxpayers, parents and teachers.
Now a website dedicated to such irreverence allows users to deface virtual textbooks creatively online.
Since its launch in July this year, kyokasho.net has recorded more than 10,000 user-generated images. Of the 350 notables up for grabs, the most popular is novelist Ryunosuke Akutagawa. His portrait has garnered 930 submissions to date.
"Not surprising," says the now grown-up Tokyo resident Yasuko Amahisa. "I used to always check his portrait in boring textbooks. Akutagawa has big impact for all students for his messy hair, grumpy face, looking like the typical mad artist. We find it easy to mock this image."
Second is Mozart with 401 entries, and third the 19th-century writer Masaoka Shiki with 341.