Lotte Frank  

A college student at Munich University is pursuing Karl Neumann's affections while simultaneously aiding his investigation into his father and late mother. When Karl rejects her, she becomes devastated but finds comfort from Nina, who later befriends Lotte, another student with similar interests in the mysteries surrounding Johan Liebert and the death of their shared research partner at Schuwald. This character is first introduced in Chapter 47 according to Wikipedia.