Thomas Benvesta is one of the four main heroes of Kuutei Senki. Born to a pirate family, he's the the youngest of the four children of Gina, who is also the leader of the group. He dreams of becoming an adventurer and wants to travel across the world and hates violence. Unfortunately, his three elder brothers are selfish,savage brutes who frequently abuse him and treat him as nothing more than a mere servent responsible for daily chores and other housework. Even his mother values treasures more than her son's life.

He banks his hopes of embarking on a journey on a piece of map he once found and kept it to himself, but one day even that is stolen from him by his elder brother Alles, prompting the family to further abuse him, and subsequently, embark upon a journey to rob the settlement mentioned in the map, and in no time they're finding map after map, and going on missions raiding one settlement after another. But is this also the chance Thomas has been looking for, to be able to free himself from the agonizing life in his family and become an independent traveller?