Cassie was cast as Manuella "Manny" Santos in 2001. This was her first real acting job and she was only 11 when it started. 

Manny Santos starts out as Emma Nelson's best friend. She is quirky, happy and very innocent. Throughout the years this changes. Manny wants to have a boyfriend and 'sexifies' her image. 

Cassie graduates from Degrassi in 2007 and is accepted into the Smithdale University acting department. 

Manny has dated several guys while attending Degrassi. Most notable are Craig Manning, Spinner Mason and Jay Hogart. 

Season 1:

Manny helps prevent Emma from becoming a victim of an online preditor.

Manny joins the local cheerleader team called the 'Spirit Squad'.

Manny helps Emma when Emma gets her period unexpectedly in school.

Season 2:

Manny and Emma crash the senior dance.

Manny develops a crush on Craig and asks him out. The date is a disaster (though Manny remembers differently).

Manny invites Sean as Emma's date to Spike and Snake's wedding, trying to get Sean and Emma back together.

Manny joins the girls' hockey team. 

Season 3:

Manny wants to be sexy, not cute or adorable so she starts dressing differently. She almost gets expelled for showing her thong.

Manny starts dating Craig, while he is also still dating Ashley. He lies to her and tells her he broke up with Ashley even though he doesn't.

Manny gets pregnant and after much consideration decides to have an abortion.

JT has developed a crush on Manny and at the end of the year they start dating.

Season 4:

Manny starts dating JT, but JT can't get over the fact that Manny once dated Craig. After a penis pump incident Manny breaks up with him. 

Manny consoles her friends after the school shooting and reconnects with Toby and JT. 

Manny starts dating Spinner, but Paige doesn't like this. Emma contracts gonorrhea and Manny tells people, which ends up in a big fight between them.

While Paige is distracted, Manny takes over spirit squad. This angers Paige even more and she takes Manny's spot. Manny and new girl Darcy come up with a way to get back at Paige. At the end-of-year dance Manny gets humiliated by Paige but also becomes Prom Queen. 

Season 5:

Manny wants to continue acting after scoring a part in last season's Jay and Silent Bob film. Casting is however not as forgiving so she wants to get a boob job. Her dad is not too happy with this and throws her out. This results in Manny getting drunk and flashing her boobs in front of a camera. Not long after the video is spread over the internet. 

Manny and Emma fight over this but make up. 

Manny and Craig get back together but also break up when he moves away to Vancouver. 

Manny and Emma make a pact to loose weight, where Emma develops an eating disorder. Manny tries to help but Emma ends up hospitalised anyway. 

The season ends with Manny and Darcy fighting over Spinner and Manny having sex. Darcy and Spinner break up as a result. 

Season 6:

Emma is dating Peter (who spread the video of Manny flashing) and this causes a rift between the friends. Luckily they become friends again. 

Darcy lets Manny back onto the spirit squad as a choreographer and they need money for new uniforms. This results in some fun photos being taken and them posted online. Ofcourse this doesn't end well either. 

Craig comes by to visit, and it becomes clear he is addicted to cocaine. Manny first wants to try it as well but soon realises it is a very destructive path he's on. She breaks up with him. 

Manny uses Liberty's birthday as a reason to throw a party, resulting in the stabing and death of JT. Manny blames herself. 

Manny starts dating Damian, which doesn't last long and they break up soon after. 

Season 7:

Manny supports Darcy after she gets raped while on a snowboarding trip. Darcy almost commits suicide but Manny finds her in time. 

Manny turns 18, and her parents want to throw her a traditional philipino party. They also want her to dance with her cousin. Manny doesn't want this, obviously, and finds help in Jay.

They become a couple, with ups and downs. This even results into a fake engagement - then into a real engagement - and then they break up.

Manny gets a starring role in the show West Drive, but decides to give it up to attend Smithdale University. 

Season 8:

Manny and Emma are now attending university. Emma has a room mate called Kelly. Kelly turns out to be a guy, and Emma fixes this, but Manny doesn't seem to be too happy about this. 

Emma and Manny try to tell Liberty that the sorority Liberty was trying to join is not good for her. Liberty ends up hospitalised with her stomach getting pumped. 

Manny and Emma are both interested in Kelly, who happens to be single so they both go after him. Kelly chooses Emma.