Since Facebook debuted in Japan in 2008, the social networking giant faced a few cultural obstacles in its bid for popularity, in a country where people are historically reluctant to share any sort of personal information on the internet. Still, new reports have shown that Facebook is gaining traction in Japan, and has beaten out homegrown rivals such as Mixi and DeNa.

Though, it would appear that the Japanese are letting go of some of their shyness, as Facebook had 13.5 million users in February, up from 6 million a year before. This puts the site at number one in that country for the first time, ahead of Mixi and Twitter.

Arvind Rajan, Asia-Pacific managing director for LinkedIn, states that “Facebook didn’t have a lot of traction in Japan for the longest time – They really did turn the corner.” Linkedin entered the Japanese market last October, and seeks to achieve Facebook’s recent success.

The issue of using ones real name online in Japan is a big deal. But, the country still warmed up to Facebook – Rajan ties the change in sensibility to the March 11, 2011 earthquake and tsunami. During the crisis and its aftermath, social networking sites such as Facebook helped families to locate each other and allowed people post and find reliable information. Rajan asserts, “the real-name case has been answered. People are getting it now.” The aforementioned is likely the first worthwhile utilization of Facebook I’ve ever encountered.

Facebook’s real name policy also makes the site relevant in forging relationships between would-be business partners in Japan. Koki Shiraishi, a Tokyo analyst with Daiwa Securities Capital Markets, says that “people started to recognize it’s suited to business because it uses real names and is not anonymous – It’s a chicken-and-egg thing: If everyone starts using it, then more people start using it.”

So, if more people start to use the chicken, more people will start to use the egg? In other words, Facebook is now popular in Japan.