From what I've been able to find, only the recent chapters have been scanlated. If you look at Mangahelpers though, they've got the Raws and scripts of all the previous chapters.
They defeat Plus but because the sheeps full power is activated , their memories can no longer be returned, so the only way for the memory to return, is for Ueki to sacrifice himself since he has the "Meet once again" zai, so he can use it to merge the two worlds together and thus returning everyones memory. But the thing is once the world is merged, he won't be able to return in a 100years. Ai crys as she begin to remember, she apologizes for forgetting him and she will remember him for the rest of her life. So the world got merged, and 1 year has passed with the 2 worlds merged, as Ai and their friends from "Law of Ueki" and "Law of Ueki+" hanging out and playing, she goes home to pick up things, but on the way by the river she sees kids picking on small animals, as she decides to help the animals, she started to have tears as she see a figure in rags stoping the kids. It turns out to be Ueki for the time movement of the other world compare to their world is 100 to 1 so he was able to return. On the final page is shows Ueki holding the little dog as Ai crys, Ueki says "I'm back"
hei thnx for the replies. too bad there's no site that provides from begining to end. i dont want to spoil stuff by reading halfway. plus i wont understand whats going on if i start halfway.. tough luck.