Creation and design
Katsura Hoshino's one shot Zone featured many characters similar to those that would appear in D.Gray-man, especially Lenalee, the Millennium Earl, and General Cross Marian. Many other characters are also "leftovers" from earlier, sometimes unpublished works.[vol. 8:40] Lenalee was one of the first characters created for the series, most notably, before Allen Walker. Hoshino based Lenalee on a real person, but has only shared her identity with her editor who laughed at the revelation. Hoshino considers her to be an ideal girl.[vol. 1:172] Her exorcist uniform was remade many times until the author was satisfied with it.[vol. 1:172] Lenalee was originally going to be portrayed as crabby and fiery based on her dark backstory, but ended up as a nice girl.
Hoshino thought that in a Victorian setting, long-haired girls tended to become the central character. After considering this, she believed a short-haired girl would stand out more and be much cuter. However, her editor wanted the character to have long hair, believing this would be better received by readers. As a result, Lenalee has long hair in the early chapters of the manga. Nevertheless, Hoshino took advantage of Lenalee's fight against the Level 3 Akuma to generate an impact strong enough to cause her to lose some of her hair in the process. Hoshino paid the most attention to Lenalee's uniform wanting to design clothing that would be sexually appealing. As a result, her uniform included a mini-skirt. However, Hoshino notes that the design does not fit with the manga's setting and states that it is best to treat Lenalee's uniform as fan service.
Hoshino enjoyed drawing Lenalee's hair, despite finding her D.Gray-man character Yu Kanda's hair impossible to top. She enjoyed drawing Lenalee because of her personality, and her relationship with other series' characters such as Komui and Reever Wenhamm. Because her hair grew longer as the series went on, the author gave her different hairstyles. When the manga moved to Jump Square, a magazine for older readers, Hoshino decided to increase Lenalee's sex appeal by having her skirt shorter even though she is also wearing shorts beneath it. After Allen Walker became a fugitive from the Order, Hoshino wanted to have Lenalee chase after him, to the point where they would clash. When asked about Allen's farewell hug with Lenalee as he leaves the Order, Hoshino joked that she was happy with how Lenalee had matured, and at the same time become taller than Allen, in contrast to the beginning of the series when they were both the same height.
Lenalee is voiced by Shizuka Itō in the original Japanese animated adaptation of the manga. Hoshino joked that Lenalee seemed more beautiful after she saw Itō's work.[vol. 9:187] Itō was replaced by Ai Kakuma in the Japanese anime sequel D.Gray-man Hallow. Lenalee is voiced in English by Luci Christian. Christian has stated she liked the character and was happy that Funimation intended to release the series' second half in 2017 so that she could voice her again. The apparent romantic relationship that grows between Lenalee and Allen in the series led to a brief video clip where Christian acting as Lenalee confesses her feelings to Allen.