After years immersed in various MMORPGs, 35-year-old businessman Kenichi Yamada seeks a fresh challenge in a never-ending game with a brutal 'Hell Mode' for hardcore players. Opting for the Summoner class, he reincarnates as Allen, an infant in a peasant family, relying on his past knowledge to progress. Struggling against the steep experience requirements of Hell Mode, Allen strives to unlock the mysteries of his chosen class while striving to emancipate his adopted kin from servitude.