Monsters: Dragon’s Hell is a spin-off of One Piece that takes place many years before the story of Luffy and company. Here the story of the samurai Ryuma is told.
Ryuma arrives in the city penniless and with an empty stomach. Luckily, a waitress from the Gèrard restaurant named Flare saved him by giving him food, but when he was arguing with the young woman about how she could pay him such a debt, a sword sheath touches Ryuma and he takes it as a duel. After Flare stops the fight, Ryuma discovers that the past of his rival and the waitress who saved him are connected by the attack of a mysterious dragon.