After the first 15 pages, the entire pool is VERY out of order.
May or may not be missing pages. There is no artist tag and pictures can only be found by searching by date (some pictures had only "marisa" as a tag). I checked between 2009-05-17 and 2009-05-28 but may have missed some pictures.
Crude summary : Marisa initially invades a human farm and is driven off by the old farmer. Eventually the old man teaches Marisa farming and fighting skills until she becomes good enough to land a blow on him. The old man eventually dies of old age and Marisa takes off the farm. A clan of wild yukkuris invade and eventually Marisa is able to kill off the invading clan.