Rose and Iris

Growing up with twin brothers, Xiu Mei was knowledgeable about games that little boys like. Added with the fact that she would sometimes train under the tutelage of her Uncle along with her brothers, she would've grown up quite boyish if it weren't for her Xiu Grandparents training her with etiquette and manners appropriate for girls. 

That's why when she volunteered at the orphanage, Xiu Mei chose to play with the little boys instead of hanging out with the girls, unlike the other female students. 

On the other hand, Ying Yue was the princess type between the two of them. She grew up learning ballet, piano, and harp. So she ended up taking care of the little girls in the orphanage. 

Their volunteer project lasted only for a month, which was spending time with the kids for five hours 3x a week. The two of them got very well acquainted with a lot of the little kids, some she even saw got adopted throughout the service.