Teen/Adult Mystery Friend Sign-Up Sheet! ♥ Teens and adults can sign up to participate by leaving weekly notes for a mystery friend starting February 5th and attending a breakfast on March 11th. ♥ Completed forms are due by January 29th and pairings will be made with elementary, middle, or high school students. ♥ Participants must commit to leaving a note every Sunday or arranging an alternative if unable to attend, and to attend the breakfast in March.