Hakata Toushirou is a tantou, or short sword, forged by the swordsmith Awataguchi Yoshimitsu, making him one of the many Toushirou brothers within the Touken Ranbu canon. His name is derived from the city of Hakata, a location historically renowned for its prosperous merchants and vibrant trade. This connection to commerce is central to his identity, as his history as a sword reflects a journey through the hands of wealthy merchants and feudal lords. He was bestowed as a gift from Kuroda Tadayuki, the lord of Fukuoka Castle, to the Ogasawara family as a token of their faithfulness, and this lineage is said to be the source of his inherited "merchant soul".

In terms of personality, Hakata Toushirou presents a charming juxtaposition between his youthful appearance and his mature, business-minded demeanor. He considers himself a sophisticated Japanese businessman, a persona that is amplified by his distinctive Hakata dialect. He is portrayed as an intelligent and energetic boy with a very bright personality. His primary focus and motivation revolve around finance and profit; he handles money with great skill and is always keen on making decisions that will yield financial gain. This singular focus often translates into a remarkable, almost supernatural, luck with currency, as he seems to have an uncanny ability to find money in odd places, such as discovering it under a rock. This trait is not just a personal quirk but a notable ability, as his presence in the citadel is associated with an abundance of koban, an old form of Japanese gold currency, which is a valuable resource for campaigns and citadel maintenance.

Within the story of Zoku Touken Ranbu: Hanamaru, Hakata Toushirou is one of the swords manifested at the Hanamaru Citadel, specifically noted to be the thirty-fifth sword obtained by the Saniwa, or master, of that citadel. His role is largely defined by this merchant personality. He approaches his duties and daily life with the vigor of a trader, and his comments from his voice actor highlight that the animated version of Hakata Toushirou possesses even more energy than his counterpart in the original game. A key element of his character is the entertaining "gap" between his childlike appearance and his sophisticated, profit-driven speech, making him a lively and fun presence in the citadel's daily activities.

Regarding key relationships, he is part of the extensive "Toushirou brothers" group, all tantou blades forged by the same smith, Awataguchi Yoshimitsu. This familial bond connects him to many other characters within the citadel. His development in the anime is hinted at by the voice actor, who aimed to portray him with heightened energy compared to the game, ensuring that his charismatic and spirited nature is fully realized on screen. This suggests a character who is consistently dynamic and engaging, with his core traits amplified for the animated medium. His notable abilities extend beyond combat proficiency; his unique and most celebrated talent is his supernatural affinity for money and treasure, making him an invaluable asset for resource acquisition within the narrative of the series.