Commander of "Black Lizard"
Hirotsu is a middle-aged man with his white hair swept back, with thin eyelashes and mustache, and a short beard ending in a spike. He is always seen wearing a monocle over his right eye. He dons a long, black coat over a white shirt with a black ribbon, along with his pants and shoes being the same color. Under said coat, he wears a dirt-brown, long scarf, and he also uses white gloves.
He is often seen smoking a cigarette.
His politeness is not only limited to his own co-workers and the public, he also shows it towards his enemies. But despite behaving as a gentleman, Hirotsu is also capable to show a ruthless side of him, whether it's to his enemies or co-workers, crudely treating them with words; this is better shown when he threatens the other two commanders from Black Lizard, or when he mocks Higuchi.
He seems to be a diligent individual, always doing a well-done job and celebrating with cigarettes, claiming that they taste exceptionally good. He also criticizes tardiness and misconduct, suggesting that he's extremely punctual and takes his job very seriously.
Despite of how ruthless he might be, he also has a caring side which is shown when he warns Higuchi, but later comes together with the rest of the Black Lizard to assist her.
Hirotsu claims that the impulsiveness that come from a young person is also justified, implying that he is a patient and understanding individual.
He mentions that he was rather headstrong when he was young.
His ability, Falling Camellia (落椿, Ochi Tsubaki?), causes things that he touches to fly back with immense force.
It has been shown that his ability is powerful enough to stop and bend steel pipes with just a touch. When used on a human body, besides launching it, it can even cause the bones to break.
It is revealed that he worked with the Port Mafia for a very long time before, even during the time when the former leader got murdered by Ougai Mori. Mori became the Port Mafia boss as of that incident in Chapter 30.
He appears inside of a certain warehouse by the Port, standing by the wall, smoking while waiting for his subordinates. When his subordinates arrive, they approach the warehouse door but Hirotsu orders them to back off. He then destroys the door with his ability, busting the door open with force. He enters a storage room filled with workers carrying unknown, heavy loads. Hirotsu interupts them, saying he is there to investigate regarding to the stolen goods from the Port Mafia in order to sell it to a black market. Based on evidence, the warehouse holds the stolen goods. As the situation goes on, one of the workers grabs a steel pipe to attempt to kill Hirotsu. Hirotsu stops the steel pipe with Falling Camelia and taunts the worker, who had witnessed the use of abilities for the first time. Hirotsu uses his power to demolish the man. Afterwards, he concludes this is the place and ordered his subordinates to kill them all. He then comments that cigarettes taste exceptionally good after a "job well done" and soon, the place explodes.
Later on, it is revealed Hirotsu is aware of Mori gaining his position through his murder, telling the boss that Dazai would understand the motive behind it.