SERIES 1
1: Original characters introduced, in order of appearance: Nick Poulos (Alex Dimitriades), Nick’s mother, Irini Poulos (Elly Varrenti), Nick’s cousin, Con Bordino (Salvatore Coco), Nick’s sister, Effie Poulos (Despina Caldis), Nick’s father, George Poulos (Nico Lathouris, also drama coach), English teacher Christina Milano (Sarah Lambert), Danielle Miller (Emma Roche), Steve Wiley (Corey Page), Alan Bolton (Jon Pollard) (originally as a background character), Rose Malouf (Katherine Halliday), Chaka Cardenes (Isabella Gutierrez), Peter Rivers (Scott Major), school counsellor Yola Fatoush (Doris Younane), teacher Graham Brown (Hugh Baldwin), principal Jim Deloraine (Stephen O’Rourke), science teacher Bill Southgate (Tony Martin), Jack Tran (Tai Nguyen), Jodie Cooper (Abi Tucker) and cafe owner Ruby St. John (Jan Adele).
5: Jodie leaves temporarily to go on tour with a rock band in Melbourne.
8: Irini dies in a car crash. Con’s parents, Helen (Barbara Gouskos) and Roberto Bordino (originally played by Francesco Caudullo) first appear as minor characters.
9: Poulos housekeeper Stella Ioannou (Peta Toppano) arrives.
10: Jodie returns.
14: Chaka moves to Darwin with her family.
16: Stella’s daughter, Katerina Ioannou (Ada Nicodemou) arrives.
21: Jack leaves temporarily to go to a selective high school (his last appearance as a main character).
26: Christina leaves to teach overseas. Ruby makes her last appearance, and Graham appears for the last time as a main character (appearing later briefly in two episodes). The warehouse makes its first appearance.
28: Stella and Katerina leave for Greece (Katerina temporarily).
29: English teacher Sam Robinson (Kym Wilson) arrives, and Helen (Barbara Gouskos) and Roberto Bordino (Ivar Kants – a different actor to previously) first appear as main characters.
30: Lucy Weston (Alexandra Brunning) arrives, and George leaves for Greece.
37: Jack returns, as a minor character.
38: Nick dies of a brain haemorrhage in the boxing ring.
SERIES 2
1 (39:) Deloraine’s nephew, Matt Logan (Vince Poletto) arrives.
11 (49): Rose and Jack leave after getting married.
13 (51): Lucy leaves on an exchange programme to Japan.
14 (52): Yola and Southgate leave after Southgate takes a job as principal of a rural school.
SERIES 3
1 (53): Sam returns.
2 (54): Katerina returns.
3 (55): Steve’s sister, Allie Matts (Inge Hornstra) arrives.
4 (56): Science teacher Andrew Bell (Ian Bliss) arrives.
13 (65): Jodie leaves to go on tour. Sam and Rivers run away together. Steve and Effie make their last appearances.
SERIES 4
1 (66): The gang finds out that Steve has died. Alan Bolton becomes a main character.
2 (67): English teacher Ronnie Brooks (Deni Gordon) arrives.
4 (69): New principal June Dyson (Diane Craig) arrives, and Deloraine retires after a heart attack.
6 (71): Con leaves for an exchange programme in the USA.
7 (72): Declan Costello (Rupert Reid) arrives.
8 (73): Stassy Sumich (Tara Jakszewicz) arrives.
13 (78): Andrew leaves for Antarctica to become a research scientist.
15 (80): English teacher Tom Summers (Simon Baker-Denny) arrives.
16 (81): Charlie Byrd (Sebastian Goldspink) arrives.
22 (87): Allie leaves for London to do a creative writing placement, and Tom is suspended for having a relationship with Allie.
26 (91): Danielle takes up a TV reporting job in Wollongong.
SERIES 5
1 (92): Dyson leaves to be with her son when he gets a job in Queensland.
3 (94): Con returns for a visit.
4 (95): Bolton takes a job as an events organiser, and Melanie Black (Rebecca Smart) arrives.
5 (96): Helen and Roberto leave to visit Con in the USA.
6 (97): Matt and Stassy leave to travel Australia together.
7 (98): The Scheppers family: Anita (Lara Cox), Ryan (Rel Hunt) and their mother, Hilary (Tina Bursill) arrive.
8 (99): Bogdan Drazic (Callan Mulvey) and principal Les Bailey (Peter Sumner) arrive.
13 (104): Mai Hem (Nina Liu) arrives, and Declan is accepted into nursing school.
26 (117): Melanie leaves temporarily to go on a student exchange in France.
31 (122): Melanie returns.
39 (130): Katerina and Charlie leave for Perth when Katerina enrols in Performing Arts school there. Ronnie leaves when Hartley High starts falling apart.
SERIES 6
1 (131): The gang transfers to Hartley Heights, and Nikki Ruark (Fleur Beaupert), Kurt Peterson (Jeremy Lindsay Taylor), Dennis Klinsmann (Putu Winchester, originally as a background character), and principal Di Barnett (Andrea Moor, also taking over as drama coach) are introduced.
3 (133): Hilary accepts a job offer in Melbourne, and teacher Gerrard Albers (Frederick Miragliotta) arrives.
4 (134): Bailey takes early retirement after he is accused of sexual harassment.
6 (136): Melanie goes to Tasmania with student Andrew McReady (David Price).
7 (137): Peter ‘D’Espo’ D’Esposito (Mario Gamma) first appears in a one-episode guest role.
9 (139): Kath (Elaine Hudson) and her daughter, Sarah Livingstone (Nathalie Roy) arrive.
20 (150): Kath and Sarah return to the country (Sarah temporarily).
21 (151): D’Espo becomes a main character when he takes over as owner of the Shark Pool.
22 (152): Mai leaves to work for a record company as a music video director, and Albers takes a job in a theatre.
23 (153): The Delaine family: Lee (Marcel Bracks), and his parents Nat (also a new teacher at Hartley) (John Walton) and Jill (Morna Seres) arrive.
24 (154): Sarah returns.
38 (168): Dennis becomes a main character.
39 (169): Nikki leaves when she is no longer able to cope with the pressures of school.
SERIES 7
5 (175): Thania Saya (Tasneem Roc) arrives. D’Espo becomes a minor character.
15 (185): Nat transfers to a school in the country.
16 (186): Ryan goes on tour with cricketing legends, and Sarah leaves for teacher training college. Kurt goes to Queensland to study marine biology, and Barnett takes a job as principal of a bigger school. Gemma Whitley (Bianca Nacson) arrives.
17 (187): New principal Alan Carson (John Gregg), Zac Croft (Luke Jacobz) and science teacher Jackie Kassis (Elena Carapetis) arrive.
21 (191): Marco Vialli (Danny Raco) arrives.
22 (192): Anita leaves temporarily after leaving Drazic for Todd Gillespie (Dominic Purcell).
30 (200): Lee and Jill leave when Lee can no longer cope with school.
31 (201): Tess (Katherine Hicks) and her father, Tim Mason (Mark Owen-Taylor) arrive.
33 (203): Anita returns after breaking up with Todd.
36 (206): D’Espo makes his last appearance.
39 (209): Gemma is expelled after pretending that Marco sexually assaulted her. Tim makes his last appearance.
40 (210): Final episode of the original run. Last appearances of: Anita, Drazic, Marco, Thania, Dennis, Tess, Zac, Carson and Jackie.