|English||J. Michael Tatum|
Loser (ルーザー Rūzā ) is a collector searching for Numbers under the guise of an art thief. He is known for announcing his thefts ahead publicly, eventually gaining popularity with the masses. He got his name because supposedly none of his thefts were successful. It is eventually revealed that his true objective is to exact vengeance against those who murdered his wife.
Loser is a man with green eyes and beige skin. He usually wears a red-and-blue outfit with a golden mask. His face is horribly deformed beneath his mask. He has never shown his face to anyone but Kyōma. Before the incident and his burnt face, he was seen as a man with short, blonde hair
Elizabeth and Loser are partners-in-crime. Loser is also Elizabeth's adoptive father, which he also gave her her name, as she was named before a number as a child.
In the past he was a top researcher for New Tesla.