Since the recent Himitsu no Arashi 5-members SP (aired on 2012.10.25) has revived the 'memory' again; I think it's a perfect time to post something related to that fated meeting during Tenjin Festival in Osaka.

Here's an excerpt from Arashi Discovery of the said airing date (transcript taken from: http://home.384.jp/mika0511/discovery26.html credit to the rightful owner); where Ohno was supposed to touch on 'Matsuri' (Festival).

"今年の夏、嵐でですね、全国ツアーやったんですけどもね、大阪が初日だったんです。
  でね、一日前の日に僕、大阪に入ったんですけどもね。
  その時にね、偶然、大阪で有名な天神祭やってたんですよ。
  そんでね、花火が上がってたんですね。
  遠くから見てて、「あー、近くで見たいっ！」と思ってね、花火大会の近くまで行ったんです。
  そしたら、そこで花火大会が終わってしまいましたっ！
  と言うことでね、近くで見れなかったって言うのがあるんです。
  いや、でも偶然にも、なんと櫻井翔に会ったんです。
  翔くんも前の日に大阪に入ってて、偶然会ったんですよ！
  もうこれは運命ですね。ビックリしました、ワタクシ。ねぇっ。
  偶然にも花火の下で出会った二人は恋に落ちたとさ。めでたしめでたーし。"

"For summer this year, right; I did nation-wide tour with Arashi, and we started in Osaka.
 Then, you see... I arrived in Osaka a whole day before (the tour starts).
 At the same time, it turns out that Osaka's famous Tenjin Matsuri was also being held.
 Due to that, there were fireworks on display.
 Watching it from afar, I thought, "Ah~ I wanna see it at a closer range!" so I went nearer to the venue.
 But as I did so, the fireworks ended!
 In other words; I didn't get to see it closely.
 But even so, I met Sho Sakurai by chance.
 Sho-kun also came to Osaka a day earlier, and unexpectedly we met!
 Really, this is what you call fate. I was so amazed. Wouldn't you be too?
 Two people coincidentally meeting under the fireworks and fell in love. In the end, they lived happily ever after."