A Japanese woman Wednesday sued three Tokyo medical schools she says rejected her because of her gender and age, in a case her lawyer said was the "tip of the iceberg".

Last year it emerged that medical universities had routinely altered the admissions test scores of applicants to keep some of them out, including scores of women.

In some cases, universities sought to keep the number of women in the student body low, and in others they discriminated against people who had applied unsuccessfully in the past or were not fresh high school graduates.

The woman filing the suit was a medical worker who decided to apply for medical school in her 20s.

She failed to get into three Tokyo universities: Tokyo Medical, Showa and Juntendo.

After the admissions scandal erupted last year, prompting a government investigation, the three schools notified her that they had indeed unfairly altered her admission test scores based on her gender and age.

The woman, who spoke to media anonymously on Wednesday, says she was told by the schools that her score should have qualified her for admission to all three institutions.