Atsuhiro Sako (迫さこ圧あつ紘ひろ Sako Atsuhiro?), also known as Mr. Compress (Mr.ミスターコンプレス Misutā Konpuresu?), is a villain affiliated with the League of Villains and was a member of the organization's Vanguard Action Squad. A nationwide wanted thief, he is seen as one of the more 'experienced' members of the league. He and the rest of his team serve as the main antagonists of the Forest Training Camp Arc.

He later became one of the nine lieutenants of the Paranormal Liberation Front, an organization formed from the remnants of the League and the Meta Liberation Army.

Mr. Compress currently serves as a commander for the "Vanguard Action Support Regiment: Brown" along with Spinner.

He'll Be Here In Little Witch Academia/My Hero Academia Crossover Show.