Looking it up, AC seems like it might mean the Sega arcade game's cards. Searching for Aoba "AC" gets YouTube videos of people using cards to make the characters appear in the arcade.
That's not something you should be crying about so quickly, now is it?
KinugasaWhyyy~?!!
Even though I went and did lots of additional voice work, and finally made an appearance in AC!!When will I get my Kai-ni~?!!
