|Affiliates|| Revy |
|Affiliation||The Lagoon Company|
|Manga||Chapter 00: Black Lagoon|
|Anime||Episode 01: The Black Lagoon|
|Japanese Anime Voice||Daisuke Namikawa|
|English Anime Voice||Brad Swaile|
Rock joined the Lagoon Company after his department chief, Kageyama, abandoned him in an attempt to cover up the smuggling operation in which Rock had been an unwitting participant. Rock is a humble and mild-mannered person despite being on the business end of guns from friends and foe alike, and often seems surprised at the barbarity of the Southeast Asian crime world. He still wears a tie and short- sleeved dress shirt and prefers to use words over weapons when interacting with others. Rock, from joining the Lagoon Company, has wondered if he is experiencing Stockholm syndrome.
Within the Lagoon Company, Rock is usually responsible for account management, diplomacy, negotiation, translation, interpretation, and the occasional errand. Having once worked in the resource investigation department of Asahi Industries, Rock is also skilled in geology. He is also a skilled linguist, being effectively bilingual in Japanese (his first language) and English as well as being familiar with other languages, including Spanish, Romanian and Russian. He also has a surprisingly high tolerance for alcohol, owing to the heavy-drinking lifestyle of a ladder-climbing salaryman. Rock's earnest personality has earned him the interest of several personalities in Roanapur, including Balalaika, Mr. Chang, Rowan "Jackpot" Pigeon, Yolanda, Eda (who develops a crush on him); and the young Garcia Lovelace, whom he trusts to the greatest degree. In many ways, Rock is the heart of the Lagoon Company, serving as a balance for his more jaded teammates and as a bright spot in the world of darkness that is Roanapur.
He is one of the "luckiest" characters in the series as he managed to survive every single thing he experienced from being taken hostage to being shot at. Thus far, he has survived the wrath of Revy, Balalaika , Roberta, and Sawyer. He is appointed personally by Mr. Chang to help Garcia Lovelace, much to Lagoon Company's disapproval. Revy comments that he's repeating his actions in Japan and his encounter with Washimine Yakuza and Yukio, which resulted in tragedy. She asks if Garcia, Fabiola, and Roberta are worth it and why she always has to stick her neck out for him. He states to her that in his homeland, that's being a gun. If Revy was the gun, he was her bullet, a silver bullet that can slay any monster, if used correctly. If not, you're nothing but prey. This gets Revy thinking as the two leave together to aid Garcia. Rock begins to enjoy his life as a pirate and becomes even more comfortable with corruption. During "Roberta's Blood Trail", Rock proves to be more cunning and manipulative, and demonstrates exceptional deductive reasoning skills, similar to those of Light Yagami from Death Note (Light coincidentally was also voiced by dub voice actor Brad Swaile), able to manipulate and change Chang's plan to sacrifice Roberta into teach the US a lesson and prevent the world from discovering Roanapur. However, doing so requires him to use the same callous, exploitative logic as Chang, and he even seems to find the sense of power over others psychologically rewarding. However this apparent change in Rock alienates and disturbs the other characters, particularly Revy and Dutch, who do not understand Rock's motives and think he simply doing it to extract a large reward from Garcia, causing them to fear that Rock is becoming more sadistic and ruthless due to being corrupted by Roanapur. However, he does it entirely because he wanted to save someone, and manages to achieve Chang's goal of keeping the US out as well as saving Fabiola, Garcia and Roberta from Roberta's increasing psychosis. Fabiola Iglesias, enraged by Rock's high risk strategy, which involved manipulating Garcia into a game of "Cambodian Roulette" with Roberta, shoots him via fake bullet. Revy later says how does it feel to still look at the city and be alive, proving that he likely hasn't changed whatsoever; only changed his tactics.
While Rock has a family in Tokyo, he does not seem to have much connection to them due to their somewhat apathetic attitude towards him. It was later revealed that Rock did not pass his college entrance exams on his first try, leading his family to lower their expectations of him. It is known that Rock has a father, a mother, and an older brother who was academically capable (and thus attained a job in the Japanese government).
Dutch has stated that he believes Lagoon Company is complete with Rock not holding a gun, saying his bullets are the kind to ricochet back at them.
He was born in the 49th year of the Showa period according to the manga, which corresponds to 1975-1976.