Kazuma Kaneko

In the year 1492 of the Gregorian Calendar, in the Eastern Kingdom of Mikado… The Samurai guard the Luxurors and Casualries - the people - of Mikado. The wild Samurai Walter seeks to improve his self-taught, but unrefined skill. The Samurai Gina keeps a close, worried eye on the wild Walter. One night, the pair, while keeping watch, are suddenly transported to an unknown world… There, they see a tyrant - a demon that is far stronger than any they have encountered! As a result of the battle with the tyrant, the fate of this pair begins to shift…! Part of the Megami Tensei series ( https://mangadex.org/quick\_search/shin%20megami%20tensei )

When a demon kills young Jonathan's caretaker, he and Asuma make a vow with each other to become stronger. Ten years later, the pair meet once more after a rite where they are chosen as Samurai to defend their countrymen. Have they really achieved their goal…?