The controversial couple made national headlines in 1997 when Letourneau, then a 34-year-old teacher from the Seattle area, had an affair with Fualaau, her 13-year-old student. Letourneau served seven-and-a-half years in prison for her crime. Letourneau was released in 2004, and she and Fualaau married in 2005.
In the interview, Letourneau will discuss with Walters her plans to teach again, Fualauu's struggles with alcoholism and depression, and how the couple overcame their age difference in their relationship.
Letourneau told Walters she always intended to marry Fualaau when their liaison began. "We've always planned that and it hasn't changed," she said.
The couple's two children, who were born before they were married, will also be featured in the special. Daughters Audrey and Georgia are now older than Vili was when Letourneau became pregnant.
Watch the exclusive interview on ABC's 20/20 this Friday, April 10 at 10 p.m. ET|9 p.m. CT.