Nako is from the Japanese 菜々子 — na (greens, vegetables) + ko (child).
Nako 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 Nako reduce to 5, The Seeker. This is a traditional interpretive system, not a factual claim about the name.