He overlooked the fact that the feelings he was having were on the border between friendship and another emotion . When Ruki came out of the bathroom he saw Kai standing there , on the bed , his hand on the pillow he had slept on , looking lost at him . And then and there he saw how much he had hurt Kai with his attitude . He knew he had been acting cold when he should have just bore his chest and he could n't bear to see pain in the other man 's eyes .

Question: Why is Ruki having a change of heart ?
Answer: They are seeing the hate Kai has for them .They are seeing the harm done to Kai .They are seeing the response Kai is getting .They are seeing the love Kai is getting .