Bra is from the Japanese manga — modern formation in Akira Toriyama's Briefs-family naming convention. The Dragon Ball manga has sold over 350 million copies worldwide. Bra is the daughter of Bulma and Vegeta, younger sister of Trunks, and the only female half-Saiyan princess of the Saiyan royal lineage.
Bra does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
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In Pythagorean numerology the letters of Bra reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.