Here are some small history lessons behind
the names of some of the characters and
places in Gintama!
Yoshida Shouyou (吉田松陽)
Shoyo-sensei, the teacher of Gintoki, Katsura, Takasugi, and others during the previous war receives his name from Yoshida Shoin (吉田松陰) who once became the teacher of Takasugi Shinsaku and others. Shoin began to study tactics when he was 5, attended college when he was 8, and even taught in college when he was 9. At one point, Shoin was sent to a jail and sentenced to house arrest. He ran a school in jail, and after being released he taught the youth about military arts and politics. His students travelled around Japan in his place as he was forbidden to.
Takasugi Shinsuke (高杉晋助)
Based on Takasugi Shinsaku (高杉晋作), a samurai who founded and commanded the Kiheitai in an effort to fight against the Bakufu. His actions eventually lead to the Meiji Restoration.
Kawakami Bansai (川上万斉)
The assassin/hitokiri of the Kiheitai is based on Kawakami Gensai (河上彦斎), a highly skilled samurai of the Edo period who was one of the four notable assassins of the Bakumatsu period.
Sarutobi Ayame/Sacchan (猿飛あやめ/さっちゃん)
Gets her last name from Sarutobi Sasuke (猿飛佐助), a ninja in children's stories.
Kijima Matako (来島また子)
The gunner of the Kiheitai, though nothing alike, may have gotten her name from Kijima Matabei (来島又兵衛), a samurai who served Lord Mori.
Yagyu Kyubei (柳生九兵衞)
Based on Yagyu Jubei (柳生十兵衞) who was later regarded as the best swordsman of the Yagyu Clan. There is a legend in which Jubei had only one eye and wore an eyepatch. The "kyuu" in Kyubei is the word for "nine", and the "juu" in Jubei is the word for "ten".
Hattori Zenzo (服部全蔵)
Our JUMP-loving shinobi is named after Hattori Hanzo (服部半蔵), a famous samurai who served Tokugawa Ieyasu and was known to be fearless during his work. He is often portrayed as a ninja in popular culture. The ninja group Oniwabanshu (お庭番衆) that Hattori and Sarutobi are a part of is based on a group of ninja of the same name who served under Tokugawa Yoshimune.
Doromizu Jirocho (泥水次郎長)
Shimizu Jirocho (清水次郎長), a famous member of the yakuza. After joining up with gamblers and having a drunken fight with some hoodlums, he left his wife and business as a traveler for three years where he made a name for himself.
His real name is Yamamoto Chogoro. "Doromizu" is "muddy water" and "Shimizu" is "clear water".
Gets his name from Umibozu (海坊主), a spirit in Japanese folklore. Umibozu is said to have a large, round head like a monk. Sorachi-sensei tags on the kanji for star (星) in front of the name, as this Umibozu travels in space.
Hiraga Gengai (平賀源外)
Based on Hiraga Gennai (平賀源内) who was a pharmacologist, physician, author, painter, and inventor of the Edo period.
Takechi Henpeita (武市変平太)
Receives his name from Takechi Zuizan, otherwise known as Takechi Hanpeita (武市半平太). Takechi was a low-ranked samurai who recruited anti-Bakufu members for his party. Being a mastermind in violent attacks is what caused his close friend Sakamoto Ryoma to be wary of him.
Okada Nizo (岡田似蔵)
Gets his name from Okada Izo (岡田以蔵), who, like Kawakami Gensai, was also known as one of the four assassins.
Yagyu Koshimori (柳生輿矩)
Kyubei's father gets his name from Yagyu Munenori (柳生宗矩), a swordsman and founder of the Edo branch of the Yagyu Shinkage-ryu school.
Yagyu Binbokusai (柳生敏木斎)
The grandpa's name is slighty based on Yagyu "Sekishusai" Munetoshi (柳生石舟斎宗厳)'s name, father to Yagyu Munenori. "Binbokusai" is a word that literally means "smells of poverty".
Saigo Tokumori (西郷特盛)
Mademoiselle Saigo of Kabukicho gets his name from Saigo Takamori (西郷隆盛) of the late Edo period, a samurai who made a huge impact in Japanese history.
The firegirl of Kabukicho receives her name from Shinmon Tatsugoro (新門辰五郎), the leader of the 10th division of Edo's Megumi fire brigade.
Ketsuno Seimei (結野晴明) and Shirino Doman (巳厘野道満)
Seimei is based on Abe no Seimei (安倍晴明) who was a famous onmyoji in the Heian Period, believed to have been skilled in manipulating shikigami. Myths involve him in magical battles with his rival Ashiya Doman (芦屋道満) who wanted to take his position. In Gintama, Seimei summons a fox-like shikigami called Kuzunoha (葛葉) who is based on the actual Kuzunoha (葛の葉), a kitsune in folklore who is the mother of Abe no Seimei.
Ishikawa Goemon (石川五右衛門), a famous outlaw who attempted the assassination of Toyotomi Hideyoshi.
Murata Tetsuya (村田鉄矢)
Based on Murata Tsuneyoshi (村田経芳) who created the Murata Gun before forging blades that were mass-produced in the army.
Brief Trio & Ieyasu (ブリーフスリー&家康)
The spirits/stands Oda Nobunaga, Toyotomi Hideyoshi, and Akechi Mitsuhide, Tokugawa Ieyasu were pretty much based on themselves. Nobunaga, Hideyoshi, and Ieyasu were famous major feudal lords (daimyo) who contributed to Japan's unification. Nobunaga had a successor Hideyoshi, who would eventually conquer Japan. Mitsuhide was under Nobunaga, but betrayed him and forced him to commit seppuku during the Incident at Honnoji. After losing his lord and his eldest son (who also committed suicide after getting attacked by Mitsuhide), Hideyoshi fought in revenge and defeated Mitsuhide during the Battle of Yamazaki. Ieyasu was the first shogun of the Tokugawa shogunate who ruled after their time. In Gintama, the symbol on the litter/kago and on his underwear is that of the Tokugawa clan crest.
Kabukicho's top cat lost his ears to protect a kitten. It may be more than a coincidence that there happens to be a Japanese myth about a minstrel known as Hoichi the Earless.
Seeing how Gintama takes place in an alternate past, it makes sense to say that Edo was what Tokyo used to be called.
Otose's Snack House is located in Kabukicho outside of the city where the terminal is. Yep, there's an actual Kabukicho in Tokyo out there.
While running away from the Amanto, Katsura leads Gintoki and the gang to Ikedaya where we learn about the past, his anti-foreigner tactics and the revealment of his trick to get Gintoki to join him since they were now considered to be terrorists. Gintoki tries to persuade him otherwise but Katsura pushes on and plans to use a time bomb. Kagura mistakenly sets the timer off right before the Shinsengumi rushes in, so Gintoki takes it and runs out, and with some assistance from Kagura, chucks it up to the sky while falling out of the building. No doubt this was influenced by the actual Ikedaya Incident which involved an encounter between exclusionists and the Shinsengumi at the Ikedaya Inn.
The incident is more apparent in a Shinsengumi one-shot when they raid a hotel called the Ikezuya the night before a planned attack on the terminal.
The Yoshiwara in Gintama was an underground red-light district. It's based on the actual Yoshiwara in Edo.