Two American men are being held in Japan over the death of an Irish student.
Nicola Furlong, 21, from Curracloe, Co Wexford, was killed after she and a friend went to see a concert by the rapper Nicki Minaj in Tokyo on Wednesday night.
It is believed she had been sexually assaulted and strangled.
Diplomatic staff from the Department of Foreign Affairs are providing consular assistance to the family.
In a statement on Sunday, the family said they were devastated by the loss of their beautiful daughter and sister.
"Nicola was a warm, generous, stunning person who always had time for her family and other people," they said. "Nicola will always be at the centre of our lives. She stood for everything that is good in life."
Ms Furlong had been in Japan as an exchange student from Dublin City University. She had been studying at the Takasaki City University of Economics in Takasaki, Gunma Prefecture, about 60 miles north-west of Tokyo.
The Tokyo Shimbun newspaper has reported that two Americans, a 23-year-old dancer and a 19-year-old musician, have been arrested in connection with her death.
It is understood they are being detained on holding charges related to assault while the police investigation continues. Ms Furlong was at the concert with a friend where they met two men and the four ended up in a hotel together.
Reports in the media from Tokyo have claimed that a guest complained about loud noise from a hotel room at about 3.20am on Thursday before an employee went to the room and found Ms Furlong lying on the floor near the bed. Ms Furlong had been due to return to Ireland in July.