Though not appearing in the main story, she has been brought up in Arc 5 and is actively playing a vital role to both Heinkel and Reinhard's character arcs.
Louanna is an inhumanly beautiful woman with long blonde hair.
When Reinhard was two years old, Louanna was afflicted with a condition known as Sleeping Beauty (眠り姫 Nemurihime) and is still sleeping to this day without any changes to her body. Some time later, Ferris examined her but determined that she didn't need to be treated. Until now, she has been in this state for 17 years.