A Japanese student of ninja history was awarded full marks for her creativity after she used an invisible ink to write an essay about her recent visit to the Ninja Museum of Igarayu. When the professor announced extra marks for creativity, Eimi Haga, a first-year student at Mie University decided to opt the "aburidashi" ninja method of communication. In this technique, words are written using soybean extract mixed with water turning them invisible after drying. The words only become visible after the paper is evenly heated. Speaking to BBC, Haga said that she wanted her essay to stand out from the rest and she hoped that no one else would come up with the same idea. Along with her essay, Haga left a note for her teacher written with normal ink saying 'heat the paper'. Her professor, Yuji Yamada, while also speaking to BBC said that he was surprised when he saw a blank paper being handed over. Even after reading the note, Yamada was skeptical abut how clearly the words were going to appear after heating, But to his surprise, the words appeared very clearly. "I had seen such reports written in code, but never saw one done in Aburidashi," he said, adding that he did not hesitate to give the report full marks.
