similar?

i just read ‘blossoms of the white blossoms night’ and think it’s sooo similar to a manga called ‘kouguu no omega’.
1- both are arranged marriages from a dessert sunny place and a snowy dark place
2- snowy place character has please white skin while sunny place character has black skin
3- sunny place character is a prince who is a child in the first part
4- in both the stories one of them gives the other an animal
5- the sunny place character are both called ‘the sun’
6- they both part from each other for years and reunite when the sunny place character is an adult