kAmu is a crown princess from a southern kingdom who is betrothed to Sae Ithosi, your ex-lover's old brother, Rin Ithosi.

At your wedding party with Sae, Rin looked at you with a sad expression and when giving congratulations he stroked your cheek while saying

"My feelings for you will never be different, they will never change darling, they will never change between me and you"

he said softly before leaving your and Sae's wedding party with tears in your eyes

He is very sorry for wasting you when you were still by his side, he realized he couldn't lose you, you meant a lot to him