05/03/2025
There is a method with citrus, have you heard about it? 🥷🏼
In 2019, Japanese student Eimi Haga submitted what looked like a blank sheet of paper for her ninja history class at Mie University, but it cleverly used a historical ninja technique.
She applied “aburidashi,” an invisible ink made from soybeans, to conceal her writing, revealing it only when the paper was heated.
Her professor, Yuji Yamada, was amazed by her commitment to authenticity and praised her for achieving a level of perfection rarely seen.
Haga earned an A for creatively reviving a centuries-old method and bringing ninja history to life in the classroom.