hiyori first shoed up in ep 18 in lucky star
She was in the very first episode.
The Target Appears episode 97 of Naruto Shippuden
Episode 71 (part 2)
the wedding episode your welcome
Season 4 episode 1
He first appeared in episode 122.
Setsuna appears in the Exia Gundam in the First Episode actually.
The first episode the Warblers appeared in was the episode, "Never Been Kissed" which is the sixth episode of Glee's second season.
in episode 18
Cosmo first appears in episode 53, "A Cosmic Call".
season 2 episode 19 Ex Libris
season 1, episode 7- sub Rosa