Shun Kazama is a seventeen year-old boy. He has dark brown hair and black eyes. He is studying at Isogo High School and his best friend is Shiro Mizunuma. He is also Umi's boyfriend.
He is a member of the school's journalism club. One day, Umi saw her poem about the raised flags in the Latin Quarters Weekly, a school newspaper. Soon, Umi meets Shun when he participated a daredevil stunt and left a negative impression for Umi. Umi later accompanies her sister, Sora to get Shun's autograph at the Quartier Latin, an old building house the high school's clubs. Umi learns that Shun publishes the school newspaper along with Shiro. She ends up helping with the newspaper. Later at a debate, Shun convinces all the other students to renovate the Quartier Latin which may be demolished. The next days, the girls volunteer to help renovate the Quartier Latin.
Shun Kazama is a very inspiring boy. Back at the Conqueliot Manor, Umi shows Shun a photography of three young naval men. One of these three man is Umi's father, Yūichirō Sawamura, which was killed in the Korean Wars. Shun is shocked to see the photography because he has one just like it back home. Later, he asks his father, who reveals that Yūichirō arrived at the Kazamas home with young little Shun in his hands shortly after the end of World Wars II. Because the Kazamas family has recently lost their child so they adopted Shun and took very good care of him. Because of this, Shun started avoiding Umi in school. Umi feels very uncomfortable about the avoidance and confronts with Shun. Umi is unable to hide her feelings for Shun, and they continue as friends, just friends.
Soon the renovation of Quariter Latin is complete, but the Kanagawa Prefectural Board Of Education decided to continue the demolition. Umi, Shun Kazama and Shiro later went to Tokyo to meet with Tokumaru and successfully convince him to not demolish the old building. As they leave, Umi confesses her love for Shun, and he reciprocates her feeling in sprite of their situation.
Umi returns home and found out that her mother was back. She later questions her mother about Shun Kazama and she reveals that he is the son of Hiroshi Tachibana, The second man in the photograph. In 1945, Tachibana was killed in an accident in the repatriation ship and his mother died in his childbirth. However, Ryoko was unable to raise Shun as she was pregnant with Umi during that time. Soon, Shun was given to the Kazamas family. But Umi still have concerns about it.
Soon, Umi and Shun was summoned to the harbour and Yoshio Onodera, the third man in the photograph who's now a ship's captain. He confirms that Umi and Shun are not related by blood. With everything solved, Umi returns to the Conqueliot Manor and resumes her daily routine of raising her flags. After 10 years, they got married.