Hikari (光) is the Japanese word for "light" or "radiance." Hikari Ōe (born 1963), the autistic composer son of Nobel laureate Kenzaburō Ōe, brought the name profound resonance.
Hikari is widely used in Japan.
Hikari 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 Hikari reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.