TOKYO (Kyodo) -- Ao and Rin were the most popular names given to boys and girls, respectively, in Japan between January and September this year, an annual survey by an education service provider showed.

The two names moved up from second place last year amid a growing trend in parents choosing gender-neutral names, with the reading of the name's Chinese character or characters and the way they sound continuing to be the most important factor, Benesse Holdings Inc. said.

The kanji Chinese character meaning "blue-green," which is most often read as "Ao" but also as "Aoi," ranked first among boy's names. It was followed by Ren, meaning "lotus," and Nagi, meaning "calm," also reflecting the trend of using one character.

For girls, the kanji that means "crisp" or "cool" and which is read as "Rin" topped the ranking for the first time in 15 years. It was followed by Himari, a combination of two kanji characters meaning "sun" and "hollyhock" also pronounced Hinata, and Sui, meaning "verdant."

The survey ranked the Chinese characters most commonly used in naming a total of around 260,000 babies born to users of its services.

"It appears many parents are choosing names that convey a wish for calm or a dignified strength to help carry them through life with resilience" following many natural disasters at the start of the year, the company said.

The latest survey also saw a significant climb by the name Ran, meaning "indigo," which ranked below the top 100 last year but jumped to 39th place for boys and 71st for girls.

Its sudden popularity is believed to be influenced by the success of Japanese national volleyball player Ran Takahashi, particularly in the lead-up to the Paris Olympics this summer.

"While I have met girls with the same name (as mine), I have yet to meet any boys with it. I look forward to possibly meeting one in the future," said Takahashi.