In a stark change from the biology-related stories in previous Chapters, I would now like to move onto the subject of animals’ self-recognition in mirrors. Self-recognition is awareness of existence of the self, and can be evidence of self-awareness. Mirror self-recognition (“MSR” hereafter) where subjects recognize own mirror image as the self can explore self-awareness of animals because we can reject the possibilities of I.R.M. or Associative learning and judge that the subjects have self-awareness via their reactions to the mirror. Here, I will discuss the history of research in this particular area, as well as animals’ mirror self-recognition. The meaning of animals’ self-awareness, a subject of particular importance, will also be explored, in part in connection with cross-disciplinary studies and activities.