The couple started in Falco's First Love, when they were introduced to each other by a friend. They instantly fell in love with each other and started dating, but they kept their relationship confidential to refrain from being harassed. Soon, the students found out, but the harassment did not occur.
The couple first started in Falco's First Love, when Ballerina introduced them. 6f was a member of the mathematics team, and Falco was a new student who had skipped the eighth grade, but had to repeat the ninth grade. They instantly fell in love, and started dating, but they kept this a secret from everybody to refrain from being interpreted as "gay". Ballerina had sensed that they had been dating, but told no one. Everybody else knew what happened when they caught the two kissing, and teased them a little bit, but Ballerina told them it was okay to be gay, which saved 6f and Falco's relationship. Later in the episode, Ballerina came up with a ship name for the two: 6-Falco, which is the name of Ballerina's robot in Technology class.