Hi and welcome Clem84!
Glad to see new fans
.
Hum indeed they don't have blu-ray, but even on DVD, the quality you can have is really poor. They are recording their flights without thinking of lots of details, so the quality isn't really great. Especially for the lights. So we don't really need blu-ray for that kind of images (imo).
About the graduation of the last member (Maccochan), it wasn't the first one. At the beginning PASSPO☆ was composed of 10 girls, and Musshu (Kaho Sakuma) left the group (30/12/2011). Officially it was due to health problems. They announced her graduation less than one month before only!
Since she graduated, fans were asking questions about the futur of the group. And they decided to let the fans choose between 7 new girls. Or it was what we were thinking. The thing is that they put the 9 former members of PASSPO + the new girls in a survey, and the 10 girls with the most votes were supposed to become the new line up.
Finally, because of fans reactions, they just quit this idea and the line up stayed with only the 9 former members.
And recently, with the new graduation, the group will just stay like that.
Also, with the 7 other girls, they finally created a new group (Palet).
About how works the graduations, there's absolutely no rules with that. It depends on lots of things and how the group were thought at the beginning.
For PASSPO☆ , since they all are in the group since the very beginning, the graduation can't be decide on the criteria of "how much time they're in the group".
It's just a decision they can take when they want to leave (of course they also have a contract they have to respect).
Obviously, the age is a real criteria : at a moment, they want to have a strong relationship which is normal thing.
And in some groups, girls know that they will be forced to quit when they reach 20 or 22 years old (marketing plan).
In PASSPO's case, to be honest, we're closer to the end of the group than the beginning. The group will probably end with a disband rather than a new line-up.
However, since they are doing more and more things (writing songs, playing instruments for example), we can hope that we still have few years with them
.
We'll have more informations on the lifetime of the group with the success of the next album.