My idea for Vietnam's background:
Vietnam-chan comes from a small but lively family. She was born from the union of Dai Viet, daughter of Van Lang, and Cham Pa, son of Lam Ap. Dai Viet was a proud young lady, small in stature but strong. Champa was a knightly man, bold and splendid. Her parents grew up together (childhood friend, yay!) and they shared a mutual crush for each other, but unfortunately they were both hyperactive and both wanted to take the dominant role (^^). This resulted in endless quarrels for the couple. At young age, Dai Viet was stronger and constantly bullied Champa, prompting him to retaliate with pranks, like stealing her belongings, pulling her hair (oh that childlike affection!). When they reached their teens, Champa grew up to be a fine young man, strong and aggressive. More than once he overpowered Dai Viet that she could barely saved herself (what a smutty situation!). But as time when on, Champa matured and became gentler. He occasionally pretended to lose and let Dai Viet-chan hug him as she liked (Heart ). His maturity and unexpected gentleness made Dai Viet's maiden heart flustered. Champa sworn to be hers and take care of her, while Dai Viet promised to treasure and protect Champa Huggle! (reversed roles?). Their love crystallized into a lovely baby: Vietnam-chan.