>>23322801
>>23318473
The premise in the official site is this, which sounds fairly generic. It's either a sequel or an AU where they're reusing some terms.
>When the seal of the evil world, which once terrorized the human world, was broken, many evil soldiers began their invasion.
>Five young samurai rushed to the rescue of humanity.
>They are called Samurai Troopers!!
>A new chapter in the days of battles is about to begin!
For what's worth, "Evil World" is the same "Youjakai" 妖邪界 from the original series, rather than calling the villain's world something else. Meanwhile, the red armor has a different name. On the other hand, Gai, the new protagonist, has the same "benevolence" kanji as the original as his virtude.