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 ?
The answer to the above question:


They are seeing the harm done to Kai .