Chloe has an inner strength that I've just started to touch on. She's something of a deconstruction of a typical submissive character found in visual novels. Chloe has been through hell. You don't go through what she's been through without developing an inner strength. She did not accept the collar at first to see how he would react. Would he demand that she wear it? would he try to guilt trip her? would he insult her? No. He did something clever and made it her choice.