In this version,it seems that the Japanese localization have updated. But,still, the same part have not been localized into Japanese neatly!
The part is in the 1st.part,"Introduction" and the 3 rd. part,"Install files" in the all 4 parts processed window.
All the 4 part have localized only the buttons,not the main text body at all.
Therefore, the 1st. and 3 rd. parts have been mismatched between the descriptional body text and test on the button below in the part' window.
I suggest at least the 1 st. and 3 rd. part ,"Introduction" and "Install files", be localized a.s.a.p.