Judging by age, this should be how it will turn out but I don't think any official announcement was made was it?
Anyways, I had plenty of time to prepare myself for Gaki-san's graduation and even though I'm deeply saddened by this, after seeing how Ai-chan is continuing her activity in acting and in what she loves, I'm actually happier to see her follow her own path, and Gaki is the only graduating member that I feel this way for ♥