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Koichi Adachi (足立 宏一, Adachi Kōichi) is a one of seven playable characters appeared in Yakuza: Like a Dragon. He is a former police officer and driving instructor with the Kanagawa Prefectural Police.



Adachi has a heavy, muscular build and graying, slicked back hair with a widow's peak. He wears a blue bomber jacket with a brown fur collar and the sleeves pulled up above his elbows over white T-shirt, a pair of fingerless black leather gloves, a silver watch, khaki pants, and a pair of lace-up sneakers.


Adachi is a driven man who carries himself with a nonchalant demeanor. Despite that, he holds deep care for his companions, and responds to stressful situations with intelligent planning and quick thinking. Adachi appears as a somewhat knowledgeable person, as his past career enables him to get the grips of the criminal underworld. Being a former police officer, he's able to piece together information that the party receives to form a solid hypothesis. However, on the flip side, he's terrible with money, as he admits to spend it on drinks and women.


Adachi was originally a police officer in Kanagawa Prefecture. During the 1990s, he had taken down the Yokohama Pink Panthers, which was a group of burglars committing crimes across Isezaki Ijincho.

In a case where he was investigating a robbery and double homicide of an old couple, he would come to arrest a man named Kusumi. Kusumi, who was innocent, was sentenced to 17 years in prison because Juro Horinouchi used witness intimidation to remove any alibi, as a false arrest would cause him a scandal. When Adachi tried to take action to expose Horinouchi, he was unreasonably demoted by him to the DMV and began work as driving instructor. Out of guilt, Adachi would send money to Kusumi's son Takashi under the alias "Yamada" after his parents died and he was sent to an orphanage, a decision which would cause Adachi monetary issues.


Yakuza: Like a Dragon: 2019[]

SPOILER WARNING: Plot details for Yakuza: Like a Dragon follow. (Skip)

Adachi first appears after Ichiban Kasuga is released from prison in 2019. Upon informing Kasuga that he knows about his false imprisonment, he insists that the two of them need to go to Isezaki Ijincho in order to uncover the entire truth surrounding the aforementioned incident. Kasuga, freshly out of jail, insists that Adachi leave him alone. However, Adachi insists on following Kasuga, and tells him about how the state of the yakuza world has shifted: The Tojo Clan having fallen, and the Omi Alliance taking its place at the hands of traitor Masumi Arakawa, Kasuga's old boss.

Adachi lets Kasuga go to Kamurocho to see for himself the changes that have taken place since his imprisonment. After Kasuga sees how drastically different things are in the city, Adachi meets back up with him, explaining that his superior, Juro Horinouchi, had taken a bribe from the Omi in order to help wipe the Tojo Clan from Kamurocho, leaving it open for the opposing clan to move in and take their place. He wants evidence to arrest him and learn the truth of the Kamurocho 3K Plan that exiled the Tojo Clan.

Adachi gives Kasuga a cell phone and helps him break into an Omi Alliance officers meeting later that night, where a helicopter spots them and Adachi shows them his badge to let them know he is also an officer, separating the two once again. Kasuga is shot by Arakawa and taken to Ijincho, while Adachi is fired from his job on charges of breaking and entering, assault, and interference outside of his jurisdiction. With his pension lost and no savings to speak of, he sets off in search of Kasuga when his cellphone regains its GPS connection.

They meet up again when Adachi sneaks into Hamako's place to wake Kasuga, who is now accompanied by Yu Nanba. The three search for a job are are directed to Otohime Land and are given a job to investigate Nanoha Mukoda's suspicious behavior. They learn she is to pay a large sum of money for her father Tatsuro Mukoda at Sunlight Castle. Adachi takes them to Survive Bar for a moment of rest before they save Tatsuro the next day. They inform the chairman Ryuhei Hoshino of his underling's scheme and when they return to Otohime Land for their reward, they are met with the sight of Nonomiya's hanging corpse.

They meet Nanoha's estranged twin Saeko Mukoda. Saeko states she heard the name "Lao Ma", which Adachi states is the nickname of a Yokohama Liumang boss, Akira Mabuchi. He also assumes the police ruled the death a suicide as they did not want to get in the Liumang's bad graces. They work for the Yokohama Trading Company to get close to Mabuchi, but end up imprisoned and used by Mabuchi before being freed by an incognito Joon-gi Han. They stop a war between the Ijin Three and are directed to the Geomijul.

They are separated from Nanba due to a preexisting conflict between him and the Geomijul, and learn more about the Ijin Three's history by the three heads at Heian Tower. The details of the operation are leaked by Nanba, and Kasuga's party are asked to help the Geomijul bury evidence of the operation while Bleach Japan invades. The party's victory leads to the capture of Hajime Ogasawara, a partner of Ryo Aoki with ties to the Omi Alliance. He confirms Aoki is in league with the Omi and Horinouchi. Adachi is if Horinouchi took bribes from the Omi, but Ogasawara does not have any evidence.

Adachi helps Kasuga get closer to Aoki by revealing the existence of a hidden elevator that grants access to an underground parking lot. He is able to make the bodyguards reveal they are armed. He helps Kasuga escape after Aoki orders him to be killed following their meeting at Otohime Land. When they go to Sotenbori, Adachi, while drunk, suggests to an impatient Kasuga that he can go to the Omi Alliance headquarters, which he takes up. When they meet Masumi Arakawa, they protect Kasuga from being shot, but learn that Arakawa is not planning to harm any of them.

Following the dissolution of the Omi Alliance, Arakawa is killed, and Adachi is warned by Mamoru Takabe that he and his friends may also be targeted due to helping Arakawa disband the Omi. While trying to get close to Aoki again, Mirror Face takes on Adachi's identity to get close to the imprisoned Jo Sawashiro and fights the real Adachi. Kasuga is able to know which one is Mirror Face by taking advantage of Adachi's lack of knowledge on traffic laws. Following a confrontation, Adachi sees a bomb in their vicinity and tells everyone to run.

Now in Kamurocho to face Aoki, Adachi contacts his old friend Makoto Date for a place to stay, and he lets Kasuga's party lay over at New Serena. Aoki is baited by Kasuga's bluff of incriminating evidence, and Adachi joins the others in extracting a kill order from Aoki to ruin his reputation. While the Arakawa Family office was being searched for the evidence against Aoki, a memory drive containing proof that Arakawa bribed police officials - including Horinouchi - was discovered. Adachi sends its contents to the inspector general, leading to Horinouchi's arrest.


Fighting Style[]

Being a former detective with years of experience under his belt, Adachi is well-versed in all manner close-quarters fighting. His "Detective" job has him use a makeshift police baton in combat which can double as a club. His default weapon is a Faded Police Baton that has lost it's shine from years of use. He can easily disarm people from their weapons in one fell swoop. Being the party member with highest health and defense next to Kasuga, Adachi naturally falls into the role of the resident tank of the party. Adachi has skills that can inflict "Rage" on his opponents, which allows him to influence enemy aggression towards himself to keep his fellow party members safe. He appears to use a southpaw Kali back stance, with his baton held in his left hand. His opportune strike has him thrust his baton downward into the enemy, and his default attack has him use an overhead swing with his baton.


Yakuza: Like a Dragon[]

Ryu ga Gotoku Online[]



  1. The given height of 190 cm (6′ 3″) is based on the character model's scaling factor within Yakuza: Like a Dragon's data.[1] For Dragon Engine games, this method is believed to be very accurate (±2 cm). However, this is intended as an estimate, not a substitute for an official statistic.


  1. Ryu Ga Gotoku Studio. .BIN File — "character_model_model_data.bin". Yakuza: Like a Dragon. SEGA. PS4/PS5/XB1/XSX|S/PC. 2020.