Pleiades were the daughters of the titan Atlas and his wife Pleionis.Orionas fell in love with them and chased them in order to abduct them.Pleiades resorted to Zeus who transformed them into a constellation in order to save them.So Orionas followed them,as a constellation also,in the sky and thus Pleiades that are ahead fall in the sea every evening,in order to escape from him...Among the 2500 roughly stars of Pleiades we can only see six with the naked eye.