Found on Chuo Dori.
Onigiri specialty restaurant " Omusubi no GABA Akihabara " (since May 2013) reopened on December 1, 2012.
Set meals (from 880 yen) are now offered and a take-out corner has been added.
The set meals seem to consist of a main side dish + 2 rice balls + 3 small bowls of food + miso soup + salad, and the salad can be refilled freely.
Set meals are served from 11:00 to 18:00, and the take-out corner is open from 7:00 to 20:00.