Der Langrisser is a game made by Masaya/NCS Corp. And is the fifth installement in the Langrisser. The game has never been published in the western world and is for that reason only available in English through translation hacks (and of course reproductions!). It's likely that we can blame the flop of Warsong (A remake of Langrisser First, and the only game in the series to be released in the western world) for this: No one has dared to give the series a second try.
The game is a strategy rpg. Those of you who have played the vastly more known Heroes of Might and Magic series will know what that is. Der Langrisser is pretty similar, though, it has a more consistent story.
You have heroes (Characters/Commanders) and units. Before battles (Scenarioes as they're called in the game) you can buy equipment and hire units for your heroes. They will level up through combat: Increase their skills, change classes, learn magic, and gain access to more and better troops. A classic strategy rpg in that respect.