Fumino is a 16-year-old girl who is described as an delinquent in Kumaneko High School, although she is not. She simply interrupts bullies and other bad students in violent ways.
She has a strong personality and sometimes loses her temper. She cares deeply about her brother Teppei. Her parents died in a car accident and so she had to become responsible for her little brother. As a result, she has become more mature and practical than others her age. However, she is terrible at cooking, so she relies on Ojiro to cook for her and her brother.
Even so, she cooked some porridge with some spring onions for Kazuma when he had a high fever. While nursing him with a mask on, he told her that when he was ill, nobody went near him, so they wouldn't get sick too. He also kissed Fumino through the mask, though when he got well, he doesn't remember what he had done.
She once secretly worked in one of Retsu's construction buildings for two weeks (cleaning floors) in order to earn some money to buy Kazuma a birthday present. She bought him a green necktie.
According to chapter 17, Fumino did nothing but sleep in class for the 1st year of school, which causes other students to see her as a bad student. Now she does well in her studies, only slightly poor in English.
Kazuma calls her "Fumino-san". He's very protective of Fumino and doesn't like when other men get too close to her.
Fumino loves Kazuma very much.Ojiro Kazuma
A 24-year-old English teacher who teaches at Kumaneko High School, Kazuma is described as a "plain, glasses-wearing English teacher." Kazuma is the only one who looks for Fumino when she runs away and ends up marrying her, supposedly only to help her and Teppei. He is sometimes goofy and says he appreciates seeing Fumino's rare smile.
He asks Fumino to help him with problematic students, although he is a teacher. He has a calm and caring demeanor and cares for young Teppei more than Fumino does (according to her). He often gives Teppei candy for his hard work or just for being cute. Kazuma cooks for the family and usually sleeps much later than the rest of his family because of his dedication to teaching. Kazuma has numerous costumes for both Teppei and Fumino to wear and often dresses them up for cosplay.
Even though they are married, Fumino and Kazuma sleep separately. He occasionally sleeps in Fumino's room, but only next to Teppei. Kazuma isn't open about his past, but later in the story, it is revealed that Kazuma was once in a gang. According to his old "gang" friends, he was called Jigoku no Mā-kun (地獄のまーくん , Mā-kun from Hell) because he beat up 100 motorcycle gang members without getting a single scratch.
He still has formidable fighting abilities; shown when he beat up two guys with one hand, while with his other hand he was holding Fumino. He sadly mentions once that his family is still alive, only that they reject him because of his delinquent past. His mother has passed away. His father is a politician as revealed by Shōma.
According to Shōma, Kazuma was an excellent student, as expected from a person set to become the successor of his father. However, suddenly one day, he turned into a delinquent and left home.
Kazuma also mentions that he would like to tease Fumino first before "touching" her and very much does so every chapter. He feels that their marriage is only for Teppei's sake and that he shouldn't be "touching" her in case she leaves him for another man; which he would respect if she did. Even so, he starts developing feelings for Fumino slowly.
He joked that if they were to sleep together, she would have at least grown her breasts to a size C.