Its a fun series, so I will spoil everything.
Akumetsu is a bunch of clones made by one of the most powerful person in the world. His plan was to create a perfect body for him by transfer a lot of memory from several bodies into one perfect body. However the most perfect clone betrayed him after falling in love with one of the scientist. However the perfect clone (Ver 1) died as well.
Time passed, we have a bunch of clones gather around and join under an ideal to change to Japan because of some stupid drama.
In the end, all the clones died after government raid the clone factory. The last clone transfer the memory in the girl. The girl thus is new Akumetsu.