Shimada Seijirō

Shimada Seijirō is a member of the Port Mafia's security forces for their building. He is an Ability user with the Ability named What Lurks in the Earth.

Personality
Shimada is a prideful individual who takes his apprenticeship under Akutagawa very seriously. As one of the Port Mafia's security guards for the building tasked with protecting the upper floors of the building, Shimada sees himself as a sort of guard dog for the executives.

Shimada is also a, having a habit of using overly-grandiose words to threaten his opponents such as saying that he'd "destroy Dazai's bones in " and calling himself the "Emperor of the Spirit Realm".

Ability
What Lurks in the Earth (地に潜むもの) is Shimada's Ability that allows him to liquefy any solid surfaces. The Ability lets him swim in walls or in floors, making solid surfaces seem as if it's water. However, the effect of the liquefaction is not caused by Shimada binding his ability to the floor but rather a result of his skin coming into contact with solid surfaces. He is able to turn on or off the Ability at his own will.

Relationships

 * Akutagawa Ryūnosuke: Surprised that he took up the task of training him in the first place, gained a sense of duty towards Akutagawa.