What is life? To approach this simple but profound theme, in our laboratory, we research to observe and understand the molecular phenomena within a live cell, by bio-imaging. Specifically, we isolate the genes coding for luminescent proteins from light emitting organisms, and develop bio-sensors and imaging methods that will help understand life. These research will not only contribute to understand the fundamental phenomena of life, but also for medical purpose and drug discovery. In addition, we are developing technologies that can lead to innovative changes of our future society, such as electricity-free illumination system by inserting the genes coding for light emitting proteins into plant.