After the enigmatic mana calamity, Rudeus Greyrat and his tenacious pupil Eris Boreas Greyrat are instantaneously transported to the Demon Continent. There, they unite with Ruijerd Supardia-the erstwhile commander of the Superds Warrior organization-to establish "Dead End," a prosperous adventuring party. With their reputation growing, the trio embarks on an expedition across the continent in pursuit of returning home to Fittoa.
In accordance with counsel from Hitogami, the faceless deity, Rudeus rescues Kishirika Kishirisu, the Sovereign Emperor of the Demon Realm, who subsequently bestows upon him a potent ability. As Rudeus hones his newfound power, it may well prove to be more than he anticipated when unforeseen perils emerge to impede their journey.
Mushoku Tensei: Isekai Ittara Honki Dasu Part 2 adapts chapters 26-51 of Yuka Fujikawas manga series and volumes 4-6 of Rifujin na Magonotes light novel series of the same title.