Story highlights Family: Yumi Nakai committed suicide seven years ago after being bullied

Her parents have waged a lengthy legal battle against her daughter's school

A boy bullied into rehearsing his own suicide has shocked Japan

Japan's Education Ministry to set up a special team to help schools curb bullying

Incense burns in the corner of the Nakai family living room -- part of an altar to their daughter Yumi, who committed suicide seven years ago. Yumi was just 12 years old when she took her own life, jumping from a condominium building.

"We never saw this coming," says her father, Shinji. "She was a daddy's girl, we went swimming and skiing together and loved to take trips. I was convinced there had been a mistake."

Her mother, Setsuko, lights another candle at her daughter's altar and says a prayer for her, as she does every day. She is convinced bullying at school was one of the main reasons Yumi killed herself. In the months preceding her suicide, Yumi told her mother she was being taunted by some of her classmates.

"I called the school and spoke to her teacher," she says. "The teacher said, 'I'll deal with this problem' and never got back to me, so we assumed it was solved."

Yumi hinted at bullying in the note she left behind, writing that her decision to take her life "may be because of some of my classmates, studies and exams."

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But the parents are still fighting a legal battle with the school and the Kitamoto Board of Education. The family alleges the school was negligent in bully prevention and investigating her suicide. Shinji Nakai claims the school only showed him a fraction of the investigation they carried out -- a claim the board of education rejects.

In a statement to CNN, the Kitamoto Board of Education said it was "co-operatively investigating the cause of her suicide, hearing from her parents, collecting as much information as possible including the possibility of bullying." The school also spoke to students, but school officials found no information that connected to her suicide, they said. A recent court case ruled in the school's favor. Yumi's parents filed an appeal to a higher court on Monday.

This ongoing legal drama comes as a recent bullying case has horrified Japan. A boy in Otsu, west of Tokyo, committed suicide last year by jumping off a building after bullies allegedly forced him to practice killing himself.

Japanese media and the parents claim the boy had sought help from a teacher, but his pleas were ignored. The case has prompted the government to set up a special team to help schools and board of education curb bullying.

The new anti-bullying task force will be responsible for identifying cases of serious bullying at an early stage and giving advice to education boards and schools, said Hirofumi Hirano, Minister of Education, Culture, Sports, Science and Technology, at a press conference Tuesday.

The education ministry also announced plans to conduct an emergency survey of all elementary, junior high and high schools in Japan next month in an attempt to draw up appropriate prevention measures.

"People have pointed to how there's too much academic pressure on adolescents in Japan which creates stress and leads to bullying in schools; other people talk about how Japanese cases of bullying can be group orientated," says Sachiko Horiguchi, an anthropologist at Tokyo's Temple University.

Horiguchi, however, believes the problem is far more complex and bullying is certainly not an issue peculiar to Japan. But one issue recurring in Japan is "the problem of the school and the Board of Education failing to accept the fact there's some bullying," Horiguchi says. "That can be quite common in many schools, but it's increasingly become more difficult probably to deny that."

Yumi's parents agree. They believe there has been a cover up at her school and no one wants to accept there is a problem. "I think the problem is the evaluation-first system in Japanese education. If the school admits a bullying incident, it would affect the teacher's career," says her father, Shinji. "The members of the board of education and the school are like family members, they tend to protect each other. It's disadvantageous for them to make the investigation open, so the truth is hidden."

Yumi's parents want acknowledgment of their daughter's bullying to finally feel enough closure to be able to bury her ashes in the graveyard.

"I just want to know the truth, why did she have to die?" Shinji says. "Unless I know, I just can't accept her death."