I am looking for a manga where there is an angel princess who ran away from home and crossdressed as a boy to disguise. There is another girl who helps the protagonist - that girl is not only an angel, but she is also a guardian warrior thing (4 of them). The crossdressing girl ran away from marriage with a devil for peace. Her best friend while running away is the brother of the devil, but she didn't know he was a devil.
When angel royalty turns sixteen, they need to choose their gender. When the crossdressing girl turns sixteen, she was an ice general, but she wanted to be a lazy prince like her brothers. She had to be girl for marriage since she is the only one left that hasn't chosen her gender.