A fifteen year old prodigy, whose most prominent feature is his hair, often called "rooster hair" by his colleagues. Maruo Eiichirou is a diligent student and somewhat of a perfectionist. He earned his nickname "Ei-chan" because he keeps getting straight A's on his exams. Although an honor student, he lacks in exercise, and as a result, ends up joining the Southern Tennis Club (often abbreviated as STC). It is revealed later on in the manga that his mother was the one who suggested joining a tennis club. He starts off as a naive beginner who has trouble in trying to catch up and learn the basics. However, he soon paves his way against tougher opponents such as seeded players in prefecture tournaments. After learning he needs to improve for the upcoming hurdles he will have to face, he takes up the suggestion on flying to Florida in an attempt to improve his overall performance in tennis. Although he loses his practice matches in the first few days, he eventually improves and even beats Alex, a professional player who is included in the world's top 1000. He has romantic feelings for Takasaki Natsu or Natchan, as he calls her affectionately, his fellow club and schoolmate. Later on in the manga, they start going out.
One of Ohno's American friends, Susanna (more frequently known as Susie or Sue), is a petite girl with an avid interest in yaoi. Susanna comes off as somewhat harsh and unsociable, and startles the other Genshiken members by using crude anime and manga quotes in Japanese (written in katakana to show her unfamiliarity with the language). As she makes gains in comprehension, her responding solely in quotes makes it unclear just how much Japanese she understands, much to the chagrin of Ogiue and others. Her extensive knowledge of anime and manga quotes suggests that Susanna is well-versed in both, having seen Neon Genesis Evangelion, Kimi ga Nozomu Eien, Fist of the North Star, Saint Seiya, Neko-Yasha, Mahoromatic, Azumanga Daioh, Doraemon and Lupin III, among others. She also seems to be obsessed with Japanese culture. As for her age, it is undetermined, and those who would know (i.e. Ohno) refuse to tell. Susanna wishes to study in Japan in the near future. In the relaunch of the manga, Sue has transferred to Shiiou University and is a first-year student and new club member of Genshiken. She is very close to Ogiue and still spouts various anime and manga quotes. She is employed by Ogiue to be one of her assistants for the official manga Ogiue is writing and drawing. (Source: Wikipedia)
Hedoro is a monster that befriends the Yoruzuya. He is known to love nature and has a bright flower on top of his head, in contrast to his rather ugly face.
Birthday: August 5 Zodiac: Leo Height: 163 cm Weight: 45 kg As of episodes 84-85, their gender remains unknown. Haji is Kozenigata's sidekick. Before joining Kozenigata's team, they were a thief.
Birthday: 23 Sep / Libra Age: 29+ Height: 177 cm Weight: 55 kg Previously known as Kuroita Hachirou before cosmetic surgery. Presently No.1 Host in Kabuki District. Owns/runs his own male host club by the name of Takamagahara 高天原. (Source: Gintama Wikia)
Birthday: December 14 Zodiac: Sagittarius Species: Human Height: 163 cm Weight: 45 kg Ketsuno Christel, more commonly known as Ketsuno Ana, is a popular weather girl and reporter from the Oedo news on whom Sakata Gintoki of the Yorozuya has a major crush. Aside from her dayjob as a weather girl and a reporter, she also serves as an Onmyouji during nighttime. Usually jolly and cheerful, she had a moment of notable change in her personality after she married Shirino Douman, during which time she would become weaker every day and sit alone on the porch of their house, gazing into the sky. It is hinted that it wasn't the marriage itself that was the reason her personality changed so much, as there were various flashbacks where she got along well with Douman in her childhood, but rather that she had to quit her dayjob. However, after they had been divorced and she returned to her position as a weather lady, she became her old self again. Later on, she would hire the Yorozuya when the Shirino clan used sorcery to alter the weather, so that her weather reports all became wrong, as seen in the Exorcist Chapter.