Open Sesame is a manga series by Kawakata Kaoru and published by Kodansha. Open Sesame tells the story about amateur boxing champion Danjou Yamato, who moves to Tokyo with his family, and Maki Mogami, the daughter of a highly respected doctor, and their relationship as they transform from bitter rivals to close friends.
Danjou Yamato is a high school student who lives in the countryside and is the boxing champion of the region. However, when his family has to move out to live in Tokyo, he is transferred to a school in Tokyo that was previously an all-girls school. Girls have a lot of power and give the guys a hard time. But Yamato will not bow down to the power of the girls, and on his way to claim power for the guys in the school, he finds out something about his past...something that he had forgotten long ago...
Yamato Danjou (壇上大和 Danjou Yamato?)
- The story's main character. His family moves from Nami Island to Tokyo. Yamato is the Tokai regional boxing champion. When Yamato arrives at his new school he is shocked to discover that the class was mostly girls. He soon finds out that there some boys there but that there were only nine. He also learns that the girls are the main power in the school, and becomes enraged by this when he is ordered by some girls to clean the girls washroom. He bluntly denies and snaps back at them telling them to clean the washroom. Soon after Yamato engages in a type of war against the girls where he begins to secure a place of power for the boys and even creates a boxing club. Yamato is shown to be extremely strong and quick, as shown when he is able to put a sizeable dent on the class blackboard with his bare hands and knock out an opponent in 10 seconds. Over time however an assortment of girls throughout the school begins to have crushes on him. He is shown as a popular person later in the manga and has not yet formed any love relationships with anyone in the school. But he and Mogami seem to be growing closer and closer together. After an incident where Mogami's kindness reminds Yamato of his mother, he realizes he may be in love with Mogami. When Danjou tells Mogami that he loves her she is listening to her ipod so she did not hear (from Danjous view). It is later revealed the batteries of the ipod were dead and she did hear him. She later admits that she too loves Danjou.
Maki Mogami (最上 槙 Mogami Maki?)
- A classmate of Yamato. She is first seen helping Yamato when he was dealing with city thugs. She even gives him her handkerchief, later when she discovers Yamato's name and that he was attending the same school she was, she flipped him with a throw. It is entirely unclear why she dislikes him but it apparently has to do with a past that Yamato has completely forgotten. Mogami is at first shown to be a bossy and rude person who wants things done her way or no way at all and in quite a few instances strikes Yamato for things that are not his fault. Later she still retains her bossy attitude but has mostly faded to insulting Yamato at every possible chance she can get. Despite this she and Yamato seem to retain a love/hate relationship and get along generally well, even though she seem to get jealous easily when girls pay attention to Yamato. Yet Mogami is still troubled by Yamato's seeming loss of memory over an incident that happened on Yamato's home island; an event Mogami witnessed, but won't speak of. When Danjou tells her he loves her her ipod was out of batteries and hears him, but pretends she didnt and that that i pod was on. Later, she admits to him that she heard him and asks him to say it again. After he tells her again that he loves her, she turns him down. Later, she explains to him that she does like him but as long as he can not remember what happened in the past, their relationship can go no further.
Yura Tachibana (橘由良 Tachibana Yura?)
- She has dyed hair and works as a magazine model and advertisement girl having the support of fans and photographers. Her first kiss was with Yamato and was used for a photo in a magazine article.
Tone Haruna (刀根榛名 Tone Haruna?)
- She has short hair and is very athletic with a good body. Plays all sports and has many female fans. Also an important member of the school basketball team, dating a freshman.
Koume Suzuya (鈴谷小梅 Suzuya Koume?)
- Even though she looks like a child she is a famous lead singer of a music group as well as the head of the music club. Koume initially disliked Yamato but started to soften up when Yamato dove into the swimming pool during a competition to save her. She developed a temporary crush on Yamato which partially faded when a university student protected her from a pervert. She eventually starts dating Tamanami Youji who is part of Yamato's boxing club. She also has the habit of saying Myo like a cat.
Shino Akidzuki (秋月志乃 Akidzuki Shino?)
- She wears glasses as is a prodigy an avid bookworm and takes the role of librarian. She is also very active in archery. After an incident with a boy she liked she started to warm up to Yamato and eventually started to like him but knew nothing would come from it because she knew she would be leaving to study abroad which she did in Chapter 36. She came back in Chapter 77 and confessed to Yamato.
Aoi Minakami (水上葵 Minakami Aoi?)
- Yamato's childhood friend and relationship serious girl. She has always had deep feelings for him and was taught many things by Yamato.
Aoba Yoshida (吉田青葉 Yoshida Aoba?)
- She is a transfer student that use to live in Hokkaidou. She joins the boxing club and becomes its first female member. Shortly after she takes a liking to Yamato.
Chihaya Matsumoto (松本千早 Matsumoto Chihaya?)
- Chihaya first met Yamato at a mixer and became centered on him when he didn't pay attention to her like the other guys since she craves attention. Determined she asked him out in a sneaky way to try and win his heart and almost went as far as almost kissing him but was interrupted by a guy she had done the same to previously. She found that Yamato doesn't take the notion so likely which only made her like him for real.
Aya Famitsuki (文月彩 Famitsuki Aya?)
- She joined the school the year after Yamato. On her first day she had a sparring match with Yamato who was trying to recruit new members. She got one hit by tricking him which meant she won and he asked her to join but she told him she was join the tennis team. At first everyone thought she liked Yamato by her actions to find out she actually has a crush on was actually Maki who she also calls Big Sis.
Kaya Mogami (最上香也 Mogami Kaya?)
- Maki's younger sister. Kaya is a middle-schooler in the same class as Yamato's sister, Yayoi. Kaya develops a crush on Danjou when he risks his life to push her out of the way of a speeding car. Kaya's childhood friend and classmate, Junpei, later challenges Danjou to a fight when he hears that Kaya likes strong men.
Mutsuki (睦月 Mutsuki?)
- He is currently not introduced yet but when ever Maki sees a picture she has expression of sadnes, also in the pictures he seems like a friend of Yamato. When Yamato was stuck in a strod and in a cavern Maki heard Yamato say "run, run, run away Mutsuki!" But as of now, he has been shown as to have passed on with Danjou not remembering any part of it and only having finding out again because he had went back to Nami Island to try to ask Mutsuki on what is the past between him and Maki. But, Danjou on his arrival to Nami Island, finds Mutsuki's grave.
Yayoi Danjou (壇上弥生 Danjou Yayoi?)
- Yamato's Sister. Goes to a different school and is friends with Maki's Sister. She is dating a boy from another school.
Sumire Danjou (壇上スミレ Danjou Sumire?)
- Yamato's pet chicken that he carries around with him. Yamato raised him since he was an egg. Has a tendency to snuggle up to the girls in the series and peck at his owner a lot. Often referred by Yamato as his "emergency food supply".