The island of Radja was a peaceful place, ruled by a benevolent king. But one day, monsters have invaded the island. Both the prince and the princess of the kingdom were abducted. The king summons Shami, who, despite being a cute young girl, is the most powerful warrior of the kingdom. Shami has first to rescue the king's children, and eventually to find out the source of the demonic invasion.
Gameplay-wise, Branmarker mainly follows early Dragon Quest template: it is a top-down RPG with random turn-based battles viewed from first-person perspective. The player controls Shami and another character who joins the party. Shami can cast a variety of offensive and healing spells, the majority of which must be found in treasure chests located in the dungeons rather than bought or learned. The main gameplay takes part in hostile areas, which are reasonably complex and maze-like, taking a while to explore. Leveling up is automatic, and combat mechanics are basic Japanese RPG fare. What makes it different are the various anime-style cutscenes scattered through the game, most of which feature nudity and erotic content.