It may be a romance between another character such as Ming Ming etc. Where maybe Ming Ming has feelings for ryo, but he's focussed on the lan di situation. Also, whilst everything goes on, shenhua and ryos relationship could get deeper, but maybe not exactly to the level of a couple, but definitely a form of love.
Who knows....
It might just be a scenario a bit similar to nozomis where ryo and shenhua have deep feelings for each other, but never formally express it. When eventually shenhua leaves ryo to travel to
the afterlife once she is sacrificed to save the world. Lol