This Frontiers Research Topic on ‘Neural Circuits: Japan’ explores the diversity of neural circuit research occurring across Japan by innovative researchers using cutting-edge approaches. This issue has brought together papers revealing the development, structure, and physiology of neuronal circuits involved in sensory perception, sleep and wakefulness, behavioral selection, and motor command generation in a range of species from the nematode to the primate. Like the USA and Europe, Japan is now making a strong effort to elucidate neural circuit function in diverse organisms by taking advantages of optogenetics and innovative approaches for gene manipulation, traditional physiological and anatomical approaches, and neural pathway-selective inactivation techniques that have recently been developed in Japan.