Atsuhiro Sako/Relationships

Vanguard Action Squad
Mr. Compress appears to have a sense of loyalty to Tomura Shigaraki and the rest of the League. He is dutiful in carrying out objectives. During the forest training camp, Mr. Compress captures not only Katsuki Bakugo but also Fumikage Tokoyami believing him to be beneficial to the group after seeing Dark Shadow's rampage take out Moonfish. When Katsuki is rescued during the All Might and All For One battle he is first to respond that they can't let him escape and asks who has a long-range attack.

He acts as overseer for the other members. He regularly contacts them after All Might defeats All For One in the Kamino Incident causing the League to disperse to avoid capture.

He takes time to explain things to Himiko Toga such as when she asked about what Yakuza was and the difference between them and the League. He is also the first to react when Overhaul kills Magne which costs him an arm.

However, it is to be noted that Mr. Compress criticizes Twice for being too attached and "buddy buddy" to people when Twice insists that the League go and save Giran despite the danger.

Overhaul
Mr. Compress hates Overhaul after he destroyed his left arm while trying to stop him. After the fall of the Shie Hassaikai and the capture of Overhaul, the League assaults the police van transporting Overhaul to a hospital. Tomura tells Overhaul he hates his 'high and mighty' attitude. Mr. Compress agrees with the statement and compresses part of Overhaul's left arm, severing it at the wrist as an act of retribution.