Shin Megami Tensei IV Dengeki Comic Anthology

Akemi Nakajima is a student in the "gifted class" in his high school. After being bullied and beaten by another student who a female student invoked, Nakajima uses his advanced computer skills to create the "Demon Summoning Program." He summons demons to attack the two, but he gets carried away and ultimately kills them. Now sick with the power of the demon realm Makai in his hands, he summons the demon lord Loki. Realizing summoning such a powerful demon was a mistake, Nakajima sets out to reverse the problem he has created by any means.

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 watches keeps a close, worried watch 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...!