Usagi Yojimbo: Senso

Fifteen years in his future, Miyamoto Usagi fights with Lord Noriyuki's Geishu clan, in an all-out war against the treacherous Lord Hikiji. In the fury of the final battle, a mysterious metal rocket crash-lands from the heavens, shattering both armies and igniting a new, more devastating conflict. It will take all the considerable fortitude, ingenuity, and heroism that Usagi and his loved ones can muster to combat the fearsome extraterrestrial war machines and halt the alien invasion.

In the end, not everyone will survive to tell the tale.