In Episode 12, the Hiiragi twins accompany Konata to a Comiket. While it is Tsukasa's first time there, Kagamin has apparently visited before (with Konata). Is this earlier visit (sans Tsukasa) covered in the anime? How about the manga?
Screenshots (clickable) from E12:
From ~1:50 where Konata tries to trick Miyuki into coming along:
The following snapshots are from ~3:30.