The ASEAN music festival is tomorrow!
According to her stories, Kuu just arrived in Vietnam not too long ago.
Last time she was there was in 2011.
As VTV is a public channel there's a live stream available:
https://vtv.vn/truyen-hinh-truc-tuyen/vtv1.htm
The festival starts 8 pm Vietnamese time (from Kuu's official site).
But Idk if they're going to live broadcast or at a later time/date.
The current information just says it's going to be broadcasted (before the site stated live broadcast).
EDIT:
Ok, the official facebook page of the event says it starts 7:30 pm.
And goes till 10:30 pm.
Guess that's the correct information.
The festival is fully booked.
As I understand it is free, but you had to apply beforehand and when you were drawn you got an inviation (a ticket) for the show, for Japanese visitors as well as Vietnamese.