Between the seventeenth and the nineteenth centuries, Japanese scholars and commercial authors wrote extensively about lamps, lanterns, and candles. The forms of intellectual curiosity for lights presented in this chapter reveal original paths in Tokugawa Japan’s history of investigations and discoveries. On the one hand, they point at homegrown innovations that remove Japan from the orbit of Western knowledge; on the other, they illuminate connections with important global trends. The history of the early modern curiosity for illumination points at revolutions in knowledge that encompass the small and the large, the local and the global, and scramble the timeline of Japan’s enlightened modernity.