after you clicked on the load button a pop-up should show up. click on the model button to view and choose your models. You models will say PMD file this enables them you work with MMD
What is MMD? (MikuMikuDance)
MMD (MikuMikuDance) is a free animation Download for anyone to use their is a English version for english users I use it since I speak english if you need any help here are some MMD Tutorials That were found off Youtube.[link] [link]
For the PMD Editor I used I dunno where I download it but I will find it and give you the download once I do. PMD Editor is a well a editor for making your own characters or editing a character that has been created. There are a lot of tutorials on Youtube. if you need any help plez look them up on Youtube.
What is a Vocaloid?
A Vocaloid is a singing synthesizer application software developed by the Yamaha Corporation that enables users to synthesize singing by typing in lyrics and melody. Hatsune Miku or Miku hatsune was one of the first Vocaloid created in Japan.
I Hope this helps