[€uroMeinke]

Adding more to my above comment - I think the ambiguity is a great foil to Toru's insistance to keep things "concrete." he himself is struggling with where reality ends and the other world begins. He gives people concrete names, becasue the people themselves alone are perhaps to ethereal. In the end it may well be Toru's attempt to make sense of Komiko's infidelity, and make concrete his own ambgiguous feelings.