Kajii is as explosive as his lemon bombs. An eccentric, easily excitable man with an intense obsession over science and a lemon's shape. Kajii seldom stops exclaiming his every word, and when he's not, he's mocking his adversaries or waxing lyrical of his intelligence. For all his eccentricities, Kajii is an accomplished and seasoned science enthusiast. Kajii prides himself as a scholar of physics, applying science to every aspect of his life with multiple "experiments".