Yuuri Briar

Height: 179 cm (5′10")
Affiliation: Ostania, Ministry for Foreign Affairs (Cover), State Security Service
Occupation: Diplomat (Formerly, Cover), Counterintelligence Agent

Yor Briar's younger brother who works in the State Security Service (SSS). He keeps his job at the SSS a secret from Yor, while pretending to be a normal civil servant at the foreign ministry.

Yuri has a sister-complex, and even at an early age, he would be doing everything he could to get Yor to praise him with affection. Though this could be due to his mother dying at a very early stage in his life causing him to get very attached to Yor as a mother figure.