There is a Gundam cafe just opened in Akihabara, close to UDX. You can't miss it as it looks like a Gundam.
Cameras! There is a 6 story bazaar with lots to see and some camera dealers. South exit, head right 50m then turn left into a shopping arcade. Look for stairs/lifts to get up to the other floors.
Granny! leave her in Yodabashi Akiba 8th floor resturant area
also this huge store has a good Gundam model section (6th floor I think).
Also on the 6th floor is Gatcha Gatcha heaven, with a serious showing of these Gatcha machines.
A short walk and a touch more cultural is the Jinja dedicated to Confusious. Head towards Ochanamizu on the west side of Akiba, about 15 minutes walk at a fair pace.
In the old Akiba section many of the shops are very small and crowded, It is best not to go in these shops as a large group. split the group up for these shops.
Beware of shops displaying big Anime posters outside, these are mainly adult themed inside.
Use an online resource to plan your route before hand, print the route out and designate meeting places.
Try to visit the 100 yen shop in the station concourse, near Mcdonalds. You need to exit the south side, hard left into the concourse. This also takes you over to Yodabashi Akiba.