Season 1
Gainer lives in a Domepolis in Siberia. One day, he is unexpectedly taken to a detention center by the Siberian Railway Guards on suspicion of emigrant activity. There, Gainer meets a young man named Gain and leaves with him when he escapes. They break into a manor house and Gainer steals an Overman to fight back against the Railway Police who have caught up with them.
Gain and Gainer
Gainer Sanga, a skilled gamer, leads a normal life in the domed city of Yapan until he gets involved in a mysterious altercation, leading to the activation of an Overman.
Repayment
Explosion! Overskill
The Taste of Victory is the Taste of a Kiss
Eyes Shining Toward Siberia
Saint Reagan's Assassin
The Railroad King, Kizz Munt
A Hellish Relay Race
A Hard Struggle! Adett, the Teacher
Asham's Tenacity
Tears Can't Be Stolen
An Attack Over Enormous Stone Columns
Brunhilde's Tears
The Apparition, Dominator
Between the Schedule and Magma
A Tough Fight, Adett Squad
A World Without Lies
The Sword's Fragility
Leonetta's Nightmare
Defeated at Katezu
Overman's Darkness
The Agato Crystal
Overdevil Revival
Overmax
Inside the Ice
Gain Over