I know the cover of the story has Khaol and River but there is no possible way for the creator to spin this so that Khaol and River are endgame. Khaol doesn't deserve River. River has been with him since day one and even helped Khaol's ex-lover write him a letter just for Khaol to turn his back on him time and time again.
When Imagase says they should break up and Kyouichi just accepted it was foreshadowed in the prequel when one of his ex-girlfriends said that Kyouichi didn't argue or fight back when she dumped him. I like that it shows that he is still lacking that maturity and understanding of relationships and what it means to be in love.