Story. After Makoto Yukimura finished up with Planetes, he decided he'd had enough of outer space, so he went the opposite direction, tackling a story about vikings. The first two volumes were published in Shonen Magazine and released in their book line before Yukimura decided he couldn't handle the weekly pace, at which point the manga moved to the monthly magazine Afternoon. When the 3rd volume was ready, the first two were republished under Afternoon's line with a bit of extra content. 5 volumes so far, starting in 2005.
Shonen Magazine Edition
Volume 1
Volume 2
Afternoon Edition
Volume 1
Volume 2
Volume 3
Volume 4
Volume 5