Introducing a new character who is then inexplicably ignored for a few episodes. Often the result of a clumsy Debut Queue setup.
Alternatively, a common use of Lampshade Hanging to explain why a cast member useful to the plot isn't around. This can be to exclude a character who would make a plot end too early or because the writers want to focus on specific characters.
Poorly used, this will introduce a character who is used for a single arc and then forgotten for long periods of time. The kind of writer prone to this is also liable to keep doing it.
The trope is named after the "Green Room," a backstage area in a theatre where actors who are not required on stage can wait and preparenote , the idea being that the ignored characters are just hanging out there.
See also Offstage Waiting Room.
- In Anpanman, thanks to the large amount of characters in the series, a character can end up getting their own spotlight episode and then disappear from the series. Many characters from the early years of the show has had this happen to them, and the movie- and theatrical short-introduced characters end up having the same fate, the newer ones never being transferred into the show.
- In Kämpfer, Mikoto is seen in the first few episodes via postcards to her childhood friend Natsuru. She's seen again at the end of episode 5, but Mikoto doesn't see Natsuru till episode 6. She remains part of the cast after she returns home.
- A skillful usage of this technique is in Love Hina, where Motoko (along with her "groupies") is introduced in the first minutes of the first episode, but she immediately leaves on a training excursion, thus freeing up screen time for introductions of the other characters before she gets her turn to take center stage in the third episode. Shinobu is also seen in the first episode, but not really introduced until the second.
- In the anime of New Game!, programmer Umiko Ahagon and director Shikuzu Hazuki are introduced in the first episode, way ahead of their manga debuts. They then proceed to disappear and do nothing till the anime reaches their respective introductions. This is partly because the two work in different departments- Umiko is a programmer while Shizuku is a director- and since most of the main characters are in the character design team, Umiko and Shizuku don't interact with them on a daily basis.
- In episode 4 of Unlimited Fafnir, Honoka is introduced as a New Transfer Student in episode 4 alongside Tear. But she is quickly forgotten as the latter takes prominence in that episode. She does however interact with Yuu in the next episode after he sees her in the nurse's office.
- In season 3 of the anime adaptation for The World God Only Knows, Kanon, or rather her goddess Apollo, is taken out of commission right away in the first episode, and ends up causing Keima to undertake the conquest of the goddesses after witnessing Lune stabbing her. She doesn't appear again until around episode 8, and even then just as a brief cameo to let Keima know she's still doing okay for the most part. This conveniently allows other girls and goddesses to have more screentime with him, some whom he conquered in earlier seasons, and some who only appeared in brief scenes due to the anime skipping many chapters in the manga between season 2 and 3.
- Similar to the cartoon, The Transformers (Marvel) often did this but the Dinobots were a particular stand-out example. Their presence on Earth is hinted at in the initial miniseries and they finally show up in Issue #8 when Ratchet tracks them down to help against Megatron. They aren't seen again until Issue #19, and even then they just appear at the start to announce they're quitting Optimus Prime's command and walk off (not to be seen again for a further eight issues!), as if they've been with the Earth Autobots all along when in fact this is the first time they've been seen with them.
- The Dresden Files has Bianca's Party in book 3. Everyone and everything introduced the party has a role in the series, according to Word of God. Of all the attendees, Ferrovax went the longest without returning, finally appearing again in books 16 (Peace Talks) and 17 (Battle Ground).
- The Power of Five starts off with Matt, who then vanishes after book 2, gets a brief mention in book 3, and then is gone for the first half of book 4.
- Happened quite a bit in Code Name: Eternity due to the episodes being aired out of order. The two main characters meet a sidekick early in the season, followed by a replacement sidekick in what should have been about halfway through the season; but instead, the sidekicks seem to appear and disappear at random.
- In Doctor Who, Robot Buddy K9 is introduced in "The Invisible Enemy", then promptly breaks down for the duration of "The Image of the Fendahl", the script of which was written before K9 was added to the cast.
- Also, Robot Buddy Kamelion is introduced in "The King's Demons" and then disappears for almost an entire season, reappearing only in order to be written out. This was because the complicated and expensive Kamelion prop actually did break down, and the only person who knew how it worked had died. note
- In Doomwatch, Geoff Hardcastle is introduced in the opening episode of season two and established as having joined Doomwatch in the second episode...only to be absent from the next two episodes without a mention.
- This, mixed with Out of Order happened on M*A*S*H after Charles Winchester's introduction in the season six premiere. A handful of episodes were filmed before a replacement for Frank was found. Winchester's two-part introduction was filmed later, but aired as the premiere.
- RWBY: Adam is introduced in the Black trailer but doesn't appear again until the end of Volume 2, despite the heavy use of White Fang faunus. Similarly, Junior and the Malachite twins are introduced in the Yellow trailer but don't appear until Volume 2, despite their club being associated with Roman Torchwick from the outset.
- Goo was introduced halfway into the third season of Foster's Home for Imaginary Friends, but doesn't appear again until the fourth season, but then is almost a main cast member.
- G.I. Joe: A Real American Hero had a habit of doing this, with its ridiculously large number of characters and all.
- In the first episode Justice League Unlimited, much is made of the League's interest in recruiting Green Arrow and how important he is, only to have him not show up again for thirteen episodes.
- Miraculous Ladybug: Lila Rossi is introduced at the end of Season 1 as a new classmate, with Hawk Moth insinuating that unlike other akumatized victims, she hasn't gotten over her anger towards Ladybug for humiliating her and may still want revenge, setting her up as a potential antagonist. Although that is eventually addressed in the show, she inexplicably disappears for nearly the entirety of Season 2 with no explanation or acknowledgement of what happened to her after her debut episode, and it's not until she returns in the Season 2 two-parter finale that it's finally clarified that she's been absent due to skipping school under the guise of being out of the country doing charity work.
- Mixels, being filled with tons of new characters every series, will often shift focus onto the new characters for a long while, ignoring the previously-created ones, and then the cycle continues when a new series is added.
- My Little Pony: Friendship is Magic has several examples, considering it has tons of characters. Most prominently:
- Princess Luna makes her first non-Nightmare Moon appearance at the end of the pilot two-parter, where she is reunited with her older sister Princess Celestia, and has a party in Ponyville in her honor. She is then never mentioned again, even in passing, until her titular Season 2 episode, after which she's still seen even more sparingly than Celestia. Being nocturnal probably has something to do with it.
- The zebra Zecora has an entire episode dedicated to introducing her, then she reappears for one quick scene the next episode... and then doesn't reappear until the same episode Princess Luna returns in.
- Regular Show: Thomas was shunned to the green room having only appeared with a speaking role in the three episodes that introduce him at the start of season four. He made his re-appearance late on in season four though, twenty-four episodes later.
- The Transformers suffered from the same thing, some characters only appeared for one episode!