Most children in Japan have some kinds of personal game machines. A dwindling birthrate might be one reason for children to enjoy handheld console games because of difficulties to find neighbors to play with after school outside. This research identified the playing time of games in 5th graders according to following views, 1) how long did children play with them in a day, 2) if we would find the differences of using time between children who have many friends to play with outside after school and ones who do not have, 3) if we would fine the relationship between the lengths of playing time with games machines and emotions and 4) if we would find the differences of playing time between Japan and China which both were now in a dwindling birthrate. The results were as follows; 1) boys enjoyed games more than one hours in a day in Japan and more than two hours in weekend in both countries, 2) children who had many friends to play with outside after school enjoyed games more than children who do not have many friends around their houses, 3) we could not find the relationship between emotion and the lengths of playing games and 4) we could find many strong cultural differences about emotional scales scores.