Why is Mackerel's disappearance significant in the novel, The Wind-up Bird Chronicle?

Mackerel's disappearance is significant because it heralds the beginning of a shift in Toru Okada's life. When his wife asks him to go out into the alley to look for the cat, he discovers the stone bird, meets May Kasahara and discovers the Miyawaki's well. Also around this time, Toru meets the Kano sisters and talks to the anonymous woman on the telephone. When the cat returns home, however, everything has changed. Toru renames the cat Mackerel because the cat seems to like mackerel and because Toru decides to cut ties completely with his media-darling brother-in-law Noboru Wataya. Also, the cat's former name reminds Toru of the life he had with Kumiko, which has come to an end.