Truancy is the 48th cutscene in Run 3, if counting all of the previous hidden and optional cutscenes.
This is a minor cutscene.
After beating Level N-9, a cutscene will begin, featuring a conversation between the Skater and the Student. The Skater comments that "It's nice not to have school." The Student hesitates at first, then responds that she picked her name because she enjoys school. The Skater asks why she didn't choose to go back to the Planet, if she likes school. The Student responds, "School can wait. Science will not," and goes on to say that she could be remembered in history if she figures out how the Tunnels work, but someone else will figure it out first if she's too slow. The Skater suggests that she call herself "the Scientist," and then "the Mad Scientist", but the Student tells him that the former is already taken, and refuses the latter.
There is an awkward pause, then the Student asks the Skater the same question; "Why don't you head back?" The Skater says that school is boring, so he's just gonna skip a couple years. The Student tells him "That isn't how it works..." but lets it go so she can get back to work. The Skater says that he needs to get back to work too. When the Student asks "You have work to get back to?" he tells her, "Skating practice. Close enough," and skates off in the other direction.
- The official definition of truancy is "the action of staying away from school without good reason."