Twenty-nine years after the murder of a female student at Tokyo's Sophia University, the bereaved family and police continue to seek information that could lead to the arrest of the murderer and resolution of the high-profile incident.

Relatives of the victim, Junko Kobayashi, then 21, and others took to the streets of the capital to ask members of the public for information on Tuesday, which marked the 29th anniversary of the murder, as a suspect has yet to be identified.

"We want to keep going, so that the case is solved," a member of the family said.