Yumenberg

Yumenberg is the femslash ship between Celestia Ludenberg and Yumeko Jibami from the Danganronpa and Kakegurui fandom.

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. They both are also probably addicted to gambling - giving Yumeko's obvious obsession with it and Celestia being an Ultimate Gambler.

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 a big respect to the people they find interesting.

Fanon
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. And knowing that Yumeko would accept her fate she ended up doing so. However, it's not confirmed yet.

Yumenberg sailed as a result of both characters being fairly similar. While the two having the same colored hair and eyes makes them look like sisters.

Trivia

 * Both wear black and red clothes that fit with their hair or eyes.
 * They put their lives on the line by playing games, like Russian Roulette.
 * Their real names end with  eko . (Celestia = Taeko ; Yumeko)
 * They wear a metal accesories in their fingers. Yumeko has a ring in her left thumb and Celestia wears a Gunmetal Armour ring in her right index.
 * Celestia wears black nail polish while Yumeko wears red nail polish (sometimes seen like pink).