The Mainichi Shinbun says:

マツダは、ＪＲ東京駅の地下通路に、家族をテーマに６０組の夫婦や親子の写真を一枚につなげた総延長３１１メートルの写真広告を張り出した。今月７日発売した新型ミニバン「プレマシー」のＰＲの一環で、２８日まで掲示する。
Mazda has begun putting up a 311-meter long advertisement in JR Tokyo Station's underground walkway. The theme is "family" and photographs of sixty family groups are featured. The poster is part of the PR effort for the new "Premacy" minivan, launched on the seventh of this month, and will remain up until the 28th.

When they finish slapping that sucker on the walls, it'll be the longest advertisement ever -- the previous record was only 274 meters.

It's like Christo sold out or something.