Before you start reading -- character data comes with spoilers. Quite a few of the characters aren't introduced until very far into the story.
I haven't fully populated the cast. There are another dozen or so named characters that pop up in the story. Obviously, as I write more, new characters will arrive on the scene.
Full name: Ulf Hammargren.
Height: 181
Weight: 68
Birthday: August 15
Hair: Dark brown (later black). Short but not buzz-cut. Considered good looking but definitely not a bishounen.
Nicknamed Uffe during his earlier life.
Called Ulf by Christina.
Called Urufu or Urufu-kun by his friends and Hamarugen-san by others.
Official name Hamarugen Urufu
Observe the standard western style for writing the original name.
Main cast
Class 6:1
***
Full Name: Christina Agerman
Height: 177
Weight: 59
Birthday: May 15
Hair: Golden blond. Reaches to mid back. Almost never tied up. Stunning beauty. Former super model.
Nicknamed Tina during her earlier life.
Called Kuri-chan or Kuri-san by her friends and Ageruman-san by others.
Later called Kuri by all close friends.
Official name Ageruman Kuritina
Observe the standard western style for writing the original name.
Main cast
Class 3:1
***
Full name: Wakayama Ryu
Height: 175
Weight: 63
Birthday: November
Black hair. Take your stereotypical bishounen.
Exceptionally good looking according to Japanese standards. Extremely popular. Called Prince of Himekaizen, and was called Prince of Red Rose during middle school.
Younger twin brother.
Called Ryu or Ryu-kun by his friends and Wakayama-san by others
Main cast
Class 3:1
***
Full name: Wakayama Noriko
Height: 151
Weight: 38
Birthday: November
Short (neck fully visible) black hair. Considered very cute.
Older twin sister
Called Nori-chan or Riko-chan by her friends.
Sometimes called Noriko-chan
Later called Noriko by her closest friends
Called Wakayama-san by others
Main cast
Class 3:1
***
Full name: Takeida Kyoko
Height: 160
Weight: 52
Birthday: Mars
Shoulder length black hair. Not tied up. Considered cute, but not a classic beauty. A little chubby.
Christina's best friend
Called Ko-chan by Christina
Called Kyoko-chan by her friends and Takeida-san by others
Later called Kyoko by her closest friends
Main cast
Class 3:1
***
Full Name Matsumoto Yukio
Height: 169
Weight: 60
Birthday: February
Short hair. Fairly good looking.
Called Yu-kun by his friends, sometimes Yukio-kun. Called Matsumoto-san by others.
Later called Yukio by his closest friends.
Main cast
Class 6:1
***
Full name: Ashiga James
Barista and owner of the Haven Café
Called Ashiga-san by most.
Observe Japanese naming standards despite his foreign first name.
Supporting cast
***
Full Name: Sato Amaya
Police officer and Ulf's legal guardian
Called Amaya by Ulf
Called Sato-sensei by most
Supporting cast
***
Name(s): Watabe
Twins, soccer players
Class 3:1
Supporting cast
***
Full name: Nakagawa Akio
Principal during first year. Forced to retire before second year.
Transits 2021.
Supporting cast
***
Last name: Kondo
English teacher and home room teacher to 3:1
Marries one in the staff late first year. Forced to retire during second year.
Supporting cast
***
Full name: Ando Hiroyuki
First year, male
Member of Himekaizen Cultural Exchange Club
Class 6:1
Expelled during his second year. Transfers to Irishima High.
Supporting cast
***
Full name: Shibata Kichirou
First year, male
Member of Himekaizen Cultural Exchange Club
Expelled during his second year. Transfers to Irishima High.
Class 8:1
Supporting cast
***
Full name: Kimoshita Midori
First year, female
Member of Himekaizen Cultural Exchange Club
Expelled during his second year. Transfers to Irishima High.
Known for her mass of unruly hair
Class 2:1
Supporting cast
***
Full name: Wada Sango
First year, female
Member of Himekaizen Cultural Exchange Club
Class 3:1
Expelled during her second year. Transfers to Irishima High.
Dates Jirou-sempai
Supporting cast
***
Full name: Taniguchi Jirou
Second year, male
Member of Himekaizen Cultural Exchange Club
Class 4:2
Expelled during his third year. Transfers to Irishima High.
Dates Sango-chan
Supporting cast
***
Full name: Ito Aika
First year, female
Member of Himekaizen Cultural Exchange Club
Class 5:1
Drops out of the club during her second year.
Supporting cast
***
Full name: Inoue Fumiko
First year female
Member of Himekaizen Cultural Exchange Club
Class 5:1
Drops out of the club during her second year.
Supporting cast
***
Full name: Tanaka Dai
First year male
Member of Himekaizen Cultural Exchange Club
Class 3:1
Drops out of the club during his second year.
One of the home made brothers, not related to Hideo
Supporting cast
***
Full name: Tanaka Hideo
First year, male
Member of Himekaizen Cultural Exchange Club
Class 3:1
Drops out of the club during his second year.
One of the home made brothers, not related to Dai
Supporting cast
***
Full Name: Fukuda Sho
First year, male
Member of Himekaizen Cultural Exchange Club
Class 3:1
Drops the club year two.
Supporting cast
***
Full name: Hitoshi Nori
Called: Motor mouth
First year, male
Member of Himekaizen Cultural Exchange Club
Class 4:1
Expelled during his second year. Transfers to Irishima High.
Dates Sakura-chan
Supporting cast
***
Full Name: Ota Saki
First year, female, from Kyoto with a bad attitude
Member of Himekaizen Cultural Exchange Club
Class 2:1
Drops the club year two.
Supporting cast
***
Full name: Sakurai Sakura
First year, female
Member of Himekaizen Cultural Exchange Club
Class 3:1
Expelled during her second year. Transfers to Irishima High.
Dates Nori-kun
Initially very silent. Learns to make more space for herself during first year
Supporting cast
***
Full Name: Maria Hammargren
Ulf's wife in his first life
Memory, not even supporting cast
***
Last name: Kubo
Former classmate of Yukio in Red Rose
Class 6:1
Supporting cast
***
Full name: Kojima Hitomi
One of two major beauties in the left wing.
Waist-long black hair. Stereotyped to the 'cool beauty'.
Later member of the Himekaizen Cultural Exchange Club.
Class 6:1
Expelled during her second year. Transfers to Irishima High. Transfers back to Himekaizen at the start of second term second year.
Female
Supporting cast
***
Full name: Imai Seiichi
One of the later members of the Himekaizen Cultural Exchange Club, joined at the same time as when Takado Nao transferred from Irishima high and joined the club.
Short, dyed hair
Class 8:1
Expelled during his second year. Transfers to Irishima High.
Male
Supporting cast
***
Full name: Kareyoshi Takeshi
Teacher during first year, principal during second year, connected to Red Rose
Male
Antagonist
***
Full name: Sano Mitsuo
Christina's grandfather. In the process of becoming her legal guardian by adopting her.
Arrival and 95 years old subjectively. 40 objectively.
Exceptionally good looking according to Japanese standards.
Male
Supporting cast
***
Full Name: Takado Nao
Photo model. Second year in Irishima High.
Dyed hair. Stereotypical bishounen.
Later class 7:2 after his transfer to Himekaizen at the start of the second trimester.
Drops the club during his third year.
Male
Supporting cast
***
Full Name: Kinoshita Dai
Arrival 1986.
Male
Fashion photographer
Suporting cast
***
Full name: Goto Daisuke
Member of the judo club.
Class 9:1 (and hence a Red Rose transfer student)
Male
Huge student
Supporting cast
***
Full name: Murakami Kenshin
Student council treasurer first year.
Male
Class 6:3
Supporting cast
***
Full name: Tamura Rie
Student council president first year.
Female
Class 1:3
Supporting cast
***
Full name: Matsumoto Takumi
Yukio's father
***
Full name: Matsumoto Masako
Yukio's mother
***
Last name: Ueno
Captain of the karate team.
Male
Class 3:2
***
Full name: Hasegawa Jun
Class: 8:3 (until September 2016)
Class: N3B (after transferring to Sweden)
Ai's older brother
***
Full name: Hasegawa Ai
Freshman at Irishima High. Later class 4 – 2.
Tomboy interested in Ryu. Introduced in book one as the girl who chats Ryu up when he and Yukio are on their way to the mall.
Shoulder length dyed hair. Considered very cute. Will become a classic beauty in her twenties.
Jun's younger sister
Joins the unofficial cultural exchange club during year two
Supporting cast
***
Full Name: Ogawa Nana
Freshman at Irishima High. Later class 4 – 2.
Female
Ai's best friend.
Introduced second year when she and Ai joins the unofficial cultural exchange club (one of the unnamed girls with Ai when they first meet Ryu).
Supporting cast
***
First Name: Chiyo
Freshman at Irishima High, year two.
Female.
***
Wakayama Natsumi, nee Masuda
Ryu and Noriko's mother
Supporting cast
***
Wakayama Tadao
Ryu and Noriko's father
Supporting cast
***
Noguchi Satoru
Vice Principal Irishima high
Male
Supporting cast
***
Jennifer Cooper (Coperu Jeniferu)
Class 7:1 during year two.
Daughter of Nathan Cooper
Supporting cast
***
Nathan Cooper
US ambassador to South Korea
Jennifer's father
***
Thomas Kanovic (Kanoviku Tomasu)
Arrival from Stockholm. Former professor at Japanese Stockholm University.
Subjective age 46.
Class 3:1 during year two.
Supporting cast
***
Uchida Rika
Former Students' union chairman of the Swedish sister school.
Graduates during year two.
Jenny's best friend.
***
Hasegawa Mamoru
Ai and Jun's father