Yumenberg

Yumenberg is the femslash ship between Yumeko Jabami and Celestia Ludenberg from the Kakegurui and Danganronpa fandoms.

Canon
Since Celestia and Yumeko are from different series, they never met in canon.

Both characters' special interest is gambling. They have no problem with lying and have questionable mental stability. They also both have black hair and red eyes. Both prefer to wear dark red and black clothing. Celeste of course picked out the outfit she wears in-game, while Yumeko chooses to wear her school uniform even when she doesn't need to.

They both are also probably addicted to gambling, given Yumeko's obvious obsession with it and Celestia being an Ultimate Gambler. They are both very good at it. Celeste is described as "taking [people's] life savings and laughing while she did it," and Yumeko surprised many with her hidden skills, beating Mary in a match on her very first day at her school (Hyakkaou Private Academy).

Yumeko and Celestia both smile most of the time, even if it isn't pertinent to the situation. However, when someone irritates them, they get quite sadistic and can be really mean to the person who angered them. Both girls also show lots of respect to the people they find interesting.

Fanon
Yumenberg sailed as a result of both characters being fairly similar. Some fanwork of the ship has the two getting together for a game, since it is one of the main traits that gets fans to ship them. Others like to interpret as both being sisters due to their similarities in lookings and likings.

Since this ship is fairly unpopular, due to the two girls being part of different series, there isn't much art or writing about them. Those that exist often show an AU where Yumeko attends Hope's Peak Academy or Celestia attends Hyakkaou Private Academy. Some fan art also features the two girls mixed into one, outfit swaps, etc.

Some fans theorize that Yumeko could have received a different life schedule. This schedule could have said that she would attend Hope’s Peak as Celestia Ludenberg. However, it's a scenario only for fan fictions, as the two don't exist within the same universe.

Fandom
TUMBLR

Trivia

 * Both wear black and red clothes that match with their hair or eyes.
 * They put their lives on the line by playing games, like Russian Roulette.
 * Both characters are incredibly rich.
 * Their real names end with eko. (E.g [Celestia Ludenberg] Yasuhiro Taeko & Yumeko Jabami.)
 * When written in Japanese, the ending will still sound the same when spoken, but not look as similar as the English translation. Both names end in the character Ko (子 [child]), so that single character is the same, but the ‘e,’ sound comes from the character before and both girls have different characters before the last one. Yumeko uses a character for yume (夢 [dream, vision]) whereas Celestia has two characters for Tae (多恵 [all three characters together roughly meaning many miracles]).
 * Celestia has a cat called Grand Bois Cheri Ludenberg, whereas Yumeko herself pretends to be a cat in an episode of Kakegurui, along with spending most of her time throughout the series as a House Pet. (Female House Pets are considered to be kittens and named Mittens.)
 * Both girls wear black long stockings.
 * They both wear metal accessories on their fingers. Yumeko has a ring in her left thumb and Celestia wears a Gunmetal Armour ring on her right index finger.
 * Celestia wears black nail polish while Yumeko wears red nail polish (sometimes seen like pink).