Machiko is from the Japanese machi (真知 — true wisdom / 真千 — ten thousand truths) + ko (子 — child). Princess Machiko — Japanese heritage naming.
Machiko 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 Machiko reduce to 6, The Nurturer. This is a traditional interpretive system, not a factual claim about the name.