|Saitama vs. Subterranean King|
|Outcome||Saitama is victorious|
|Hero Saitama||Monster Subterranean King|
|Saitama is uninjured||Subterranean King is killed|
|Previous||Saitama vs. Super Custom YO649Z Mk. II|
|Next||Saitama vs. Mosquito|
Saitama vs. Subterranean King is the fight between the hero Saitama and the monster Subterranean King.
Saitama is sleeping only to be interrupted by a giant hand breaking through the wall and grabbing at his head. He is then easily thrown out his apartment by this mysterious being, only to find his house destroyed. The monster then punches him which launches Saitama and causes him to bleed. The monster claims that he is the true earthling and his population is known as the "Subterranean People". They claim that 70% of the earth dwellers have already been killed and are surprised that they have found a surface dweller that survives their punches.
Saitama begins a conflict with the subterraneans that seemingly finds him enjoying the fight he's always been looking for. He is able to kill many of the subterraneans with powerful kicks and punches until it seems that he is outnumbered. Despite this, he is able to fight with exhilaration and defeat the subterraneans that continue to come at him. Eventually he stands face-to-face with the Subterranean King, only to be interrupted by the sound of an alarm and waking up realizing it was a dream. He then hears the sound of the true Subterraneans outside his apartment trying to claim the surface as their own.
Saitama crushes the Subterranean King with ease. Afterwards, he gets excited about the fight only to find that the Subterraneans have easily surrendered.
The Subterraneans surrender and Saitama states that he's become too strong.