A memorial service was held Sunday to commemorate the first anniversary of the death of a Sri Lankan woman who died while in custody at an immigration center in central Japan last year amid calls nationwide to review Japan's detention system for those facing deportation.

Around 50 people braved the rain and wind to attend the Buddhist service in Aichi Prefecture for Ratnayake Liyanage Wishma, including her 27-year-old sister Poornima, as well as some who had previously been held at the Nagoya Regional Immigration Services Bureau, where Wishma had been detained.

Both Japanese and Sri Lankan rites were held at the temple, where Wishma's remains are being kept, with her sister expressing gratitude for the service.

Poornima (front) attends a memorial service of her sister Ratnayake Liyanage Wishma Sandamali at a temple in Aichi Prefecture on March 6, 2022. (Kyodo)

Wishma died at the age of 33 on March 6 last year at the immigration center following a month of medical complaints, including vomiting and stomachaches.

"We sympathize with the family and vow to never allow something like this to happen again," said Shoichi Ibusuki, a defense lawyer representing her family.

Related coverage:

Kin of dead Sri Lankan detainee file 156 mil. yen damages suit with Japan

Japan will not seek immigration law amendment before summer election

Family of dead Sri Lankan files criminal complaint against Japan officials

The service came after Wishma's relatives filed a suit against the government Friday, demanding 156 million yen ($1.35 million) in damages. Her family alleges she was illegally detained and died due to a lack of necessary medical care.

A crowd in Tokyo marches to demand improved treatment in Japan's detention centers on March 6, 2022, the anniversary of the death of a Sri Lankan detainee. (Kyodo)

She had arrived on a student visa in 2017 to study the Japanese language but overstayed her visa, and immigration authorities denied her asylum application.

Demonstrations were held across the country Sunday as people demanded better treatment at Japan's detention centers and a revision of the country's strict refugee recognition system. Over 300 people marched by one facility in central Tokyo.