The protagonist Edna certainly changes. She begins the story as a woman trapped in a loveless marriage. The late Victorian society in which she lives asserts that women must be angelic wives and mothers, but the free-spirited Edna, sensual and solitary, would prefer to be an artist. She is a woman out of step with her culture. Once she takes up art and a lover, she is put into conflict with this society and eventually is ostracized from it becomes too much for her. This leads Edna to drown herself in the sea.
No other character in The Awakening goes through as dramatic an arc, but a few do change by the ending. Edna's love interest Robert is one such character. At first, he seems an ardent wooer who does not care to play by society's rules, a male counterpart to Edna (emphasized by their having the same color hair). He views her as an equal in the game of love, but once he finally falls in love with Edna, he falls back on society's views about marriage and a woman's place in that relationship. He wants Edna to be "given" to him by her husband, suggesting that he now views her as an object. When he cannot possess her in marriage, Robert abandons the relationship entirely. Unlike Edna, he realizes he is unwilling to bend society's rules too far.
In the end, both Edna and Robert are changed by society's judgment. Neither is able to live without the comfort and validation of the larger social world, so Robert returns to it while Edna, unable to live in existential imprisonment, chooses freedom in death. In Chopin's novel, the actions of the characters say more about them than their words (it must be remembered that in this society, most of these characters rarely say what they mean). From their actions, it is inferred that Robert is more a part of the mainstream social order than he would like to think and that Edna is unwilling to go on without either a social safety net or the freedom she so craves.