Ren's family runs along beside her during her final pole vaulting attempt, something that would cause her to be disqualified and result in Lawrence J.H.S. losing the match.
The music heard during Louis' one-man "Romeo & Juliet" performance is Mozart's Piano Sonata No. 15 in C Major.
When Louis is solving various types of equations, you can see 'Sin Ø' around the work he's doing. That's generally a part of trigonometry equations, something only offered to 10th and 11th grade high school students.