The final performance of the Sailor Moon Un Nouveau Voyage musical will be streamed online on Niconico October 4th. Viewers in Japan can watch it using this link. This is a paid broadcast which is limited to viewing in Japan only. I managed to watch the last musical online using this system though I have not had much luck watching content that is restricted by country lately. I’ll add some details on how to view it if I figure it out. This will be a Japanese only stream with no subtitles. It will be available to view time shifted until October 12th.
Presale tickets are 2000 points, which equates to 2000 yen or $17 US, and will be available until October 2nd to purchase via the Niconico web site. Day of tickets, available from October 4th to the 10th, will be 2500 points, which equates to 2500 yen or $21 US.
Miss Dream has mentioned on their Facebook and Twitter pages that they will be recording the stream and putting together an English fan subbed version. Given their usual turnaround with subtitling things it should be available within about a week of the broadcast. Once this happens, I will be sure to mention it here.
Source: The Official Sailor Moon site