|Sylvia Mercury First|
|Full Name||Sylvia Mercury First|
|Occupation||Warrant Officer (Stars)|
|Novel||Volume 9, Chapter 2|
Sylvia warms up towards Lina easily as to follow order of disclosing Lina's identity during their missions and simply because of her personality.
Sylvia is the closest with Lina during the missions in Japan. She also live in a high class condo with Lina as a roommate while acting as her support personnel. Lina easily interact with her as she displays an older-sister-like character towards her.
Lina is sad when Sylvia is to return to their nation in order to examine and ensure her body free from the Paranormal Parasite's infection.