First Day of High School is the 75th episode of The Suite Life of Zack & Cody. It's the first day of high school for Zack, Cody and Nia. For the first time, London has to attend public school.
London is advised by Mr. Moseby that London has been expelled from Our Lady of Perpetual Sorrow. Nia will also be attending Cheevers High School. Zack and Cody arrive at Cheevers High School. Zack Meets Amber, a girl at the school but she shows no interest in Zack because he is a freshman. Later on, Zack is flirting with Amber, and her boyfriend, Vance throws Zack into a bin. Nia sees this, and beats up Vance. But they end up going to Ms. Militich’s office. Mr. Moseby and Carey show up, disappointed at the kids being sent to the office. Also, Mark shows up to Cody, asking if Cody could teach him how to be a nerd.
Another thing that happens on this day is London getting fake friends. Ellen and her gang only like London for her money, but she does not realise that. When London gets in trouble for renovating the school, her friends say they do not know her and London is sent to the office. Meanwhile, Cody is in a class. Bob is there as well, but he calls Cody a nerd because he wants to be a jock (stated earlier in the episode). Him and some other kid call Cody a nerd. Vance enters the room, and tells Cody that he beat him up before. Cody explains to Vance that he beat up his brother and offers a sign of respect. Vance thinks he is offending him, and attempts to hurt him. Bob tells Vance that he used to hang with Cody, but Vance attempts to bash Bob. Cody jumps onto Vance but Ms. Militich barges in. Cody and Vance are sent to the office.
London and Cody are at the office and Carey and Moseby return. Fortunately, Cody getting a detention does not go towards the permanent records. Also, Zack scores a study date with Amber. At detention, Vance asks Nia out. Then Zack explains that High School has it’s ups and downs.
- "I have to say, I prefer being a nerd. It's a lot more satisfying hitting the books instead of hitting someone right in the kisser!” - Mark.
- "I know. I just like people to know I'm battin' 500." - Carey Martin.
- "The only bright side of my day is that Nia's miserable, too." - London Tipton.
- "Don't make me paint you again!" - Nia Moseby.
- "Your boyfriend. (*looks shocked at what he said; Nia looks up*) The way you stood up to me was awesome. And I think you're really cute."- Vance.
- "That could be the garbage in my underpants." - Zack Martin.
- The character "Mrs. Militich" may be a reference to the history teacher Mr. Militich from Smart Guy, another series produced by Suite Life creator Danny Kallis.
- For the second time, London is sent to school where the Tipton candy counter girls go. The first time was with Maddie in private school, and now with Nia in public school.
- In this episode, only the opening scene is in the Tipton Hotel.
- The picture of the "Robots who play chess" club portrait has a picture that resembles an Australian portrait of Ned Kelly.
- When Cody asks Mark why he's in detention, he tells him that he had nothing better to do.
This referenced to the 1980s film, The Breakfast Club, where a student, Allison Reynolds, gives her reason of being in detention.