The Melancholy of Haruhi Suzumiya, Vol. 20

When Kyon arrives at school, it seems like another average day-until he realizes Sasaki has wrapped North High in a closed space. Led to the SOS Brigade clubroom by Sasaki and Tachibana, Kyon knocks (just in case) and is surprised to find not a costumed Asahina, but instead a girl he's never seen before...and a very familiar face!