Coming Tokyo from 17 to 21 April

Dear

I will come tokyo for meeting from 17 ot 21 april.
hope have friend to give me some idea for 2 days fee 20 and 21.
or if who live in Higashi shinbashi, minato ku, can give me some advice about that place.
I think to go Akihabara to buy lens for my camera.
If any one know the store sale lens with good price, plz tell me.

Many thank for any advice