Keiko (恵子) combines the Japanese kei (blessing, grace) and ko (child) — meaning "blessed child." Also written 慶子 (celebrating child) or 敬子 (respectful child). One of the most traditional Japanese feminine names.
Keiko Fukuda (1913-2013) was the highest-ranked female judoka in history (10th dan).
Keiko 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.
In Pythagorean numerology the letters of Keiko reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.