SZYJN02
In the world of Uxevar, all with magic potential are able to summon a familiar at the age of 15 and are dubbed "Summoners". They then attend a school - Excandor - and train up, getting both a rank from the ranking system and a class type.
In this world, ruins will occasionally appear out of nowhere. This phenomenon has occurred for centuries, but the cause has yet to be discovered. In these ruins, monsters will spawn, which adventurers must band together to kill before the monsters can be allowed to break free of the ruins and leave to attack the civilians. When the "core" of a ruin has been destroyed, the ruins will collapse. However, certain ruins have been left to stay to allow weaker adventurers to train up.
Our hero, Zeln, embarks on his journey!