The custom of "counting sheep" originated from Western culture, probably from some areas of Europe; generally speaking, the traditional method of counting sheep is to let people who can't sleep imagine infinite sheep. Imagine sheep jumping over a low fence one after another, counting each one as they jump, and so on indefinitely, until the sheep counter falls asleep unknowingly due to the repetitive monotonous and boring activity. Although this tradition is well known in Western culture through various media, its real application effects are not obvious, and therefore it is rarely recommended as an actual therapy with hypnosis. According to a study by the University of Oxford, "counting sheep" is actually an inferior method of aiding sleep. In the same type of method that uses imagination to consume brain power to achieve fatigue hypnosis, imagining something more complex can For example, "beach or waterfall" is even more effective.

This work is a series of so-called sleep-assisted works, recorded by well-known Japanese male and female voice actors, and officially launched by HoneyBee Company at the end of April 2007. After that, a CD will be released every month.