Enma is the Hololive ENManager. She first made an appearance during the Hololive EN Left 4 Dead Collab, in which she filled in as a 4th player for their stream. During this collaboration, Enma consistently refused healing from the other members, and fought zombies using only a Katana at 1 HP. 
Her current character design was made by Ninomae Ina'nis during one of her drawing streams. 
Is the Manager whom Ninomae Ina'nis works most closely with as noted by the members.
Gura has left Enma on read in multiple occasions, leading to her being scolded for it.
Amelia accidentally responded with "That sounds like a you problem" when Enma mentioned she was experiencing a technical difficulty during the Hololive ID 2nd Generation debut. She promptly apologized while Kiara and Ina laughed in the background.
Early on Amelia and Gura referred to their manager (Jenma) as Enma. It is unclear how much they actually worked with Enma. 
While discussing some of the accessories and actions of her new outfit, Amelia noted that Enma and Jenma have different roles.