|“||There will never be anyone like her. Ever.||”|
Mona is invited to Mike's house during a party, and it is revealed that the two are friends and belong to the same support group, headed by Jesse Lindall. Much to Aria's chagrin, she then sees Mike and Mona kissing outside of the school.
Mike and Mona are seen having a date at the Apple Rose Grille. They both seem to be enjoying themselves and talk a little about Mona as a child. To Mona's dismay, Ezra walks in. She makes the decision to go talk to him and tells him she doesn't want to help him anymore, as it's gotten too complicated.
Later, Mona comes over to Mike's house. She and Mike were supposed to watch a movie together, but she lost track of time.
Mike spots Mona outside the Brew, picking up a large box, and runs over to greet her. Upon asking if she needs help, to which she declines, Mona tells Mike she has bought whistles for every girl in school, so they can protect themselves, in case Alison's rumored 'kidnapper' is still out there. As Mona leaves for her meeting with Principal Hackett, Mike tells her that he misses her.
In the Montgomery living room, Mike and Mona are sharing a pizza when Aria arrives home. Standing up, Mike tells Mona that he will take her home, but Mona insists Mike drops her off at the library.
Sitting on the floor of the Montgomery living room, Mike listens as Mona tells him that everything about the Manhattan Project is fun and it’s the place where the Cold War started. Mona adds that “J. Robert Oppenheime is dreamy”, and laughing, Mike says that he doesn’t think he can put that in the report. Standing up, Mona asks Mike if he wants some more hot chocolate and he tells her sure.
As the film is showing in the theater, Mike and Mona look adoringly at each other. After Aria has whispered something in Mona's ear, Mona whispers an excuse me in Mike’s ear, and Mike watches as she gets up and walks from the theater.
Mona is murdered in her own home and therefore the relationship between Mike and Mona ceases to exist.
Mike walks out of the Rosewood Church following Mona’s funeral service.
In a flashback, Mike walks into Mona’s room as she’s on the phone with Lesli, “Mona”. Noticing vials of blood in a desktop systems unit that has been converted into a cooler, Mike questions what it all is, “what is this?” Picking up a blood vial, Mike wonders what the “hell” is going on, and taking the vial back, Mona tells him not to touch it, “just leave it alone and I’ll explain”. As Mona goes to close her bedroom door, Mike questions what she’s doing, and Mona tells him that she’s been offered the chance to make things right for Aria and her friends. Mike questions what Mona is talking about and Mona says that she’s talking about exposing ‘A’ and finally bringing that person down. Looking back over to the cooler, Mike wonders if it’s Mona’s blood, to which Mona says that it is, “and soon it’s going to be smeared all over this house”. Mona goes on to say that Alison DiLaurentis will look responsible for killing her because ‘A’ wants to see Alison locked up.
Mike wonders why Mona would want to be a part of all this, and Mona says that it’s because ‘A’ came up with this plan, “and it’s brilliant”. Telling Mona to stop, Mike questions that she’s been talking with ‘A’, to which Mona explains that she hasn’t directly, “but I will, eventually”. Telling Mike that she has to earn it, Mona says that to do so, she has to commit to this plan 100%, “that means I go away. And when I find out who ‘A’ is, I come back, Alison gets out of jail, and your sister and her friends are finally safe”. Disbelieving, Mike shakes his head and starts to walk from Mona’s bedroom, but stops when Mona adds that she’ll be everyone’s hero. Walking back over to her, Mike wonders what Mona means by going away and “for how long?”, to which Mona says that he needs to look at the big picture, “it’s only temporary”.
Mike tells Aria, Mona didn't want to see him, since they were rescued from the dollhouse. He thinks his sister has to do with it, but she promises she doesn't. Later that day, Mike is in Mona's room to talk to her. Although Mona first suggests him to leave, she eventually talks to him. She tells him everything she did was for nothing and she should better have stayed in the dollhouse. But Mike declares it doesn't matter what she did, all that matters to him, is her being alive. He asks Mona, if she wants him to go, as she denies, they get closer and share a kiss.
- Started: "Bite Your Tongue" (4x17)
- Reason: Mona is invited to Mike's house for a party. Later they are seen kissing outside of Rosewood High.
- Ended: "Cover For Me" (4x22)
- Reason: Mona admits to Emily that she started dating Mike so she could get closer to Aria and find out information for Ezra, but she fell for him.
- Mona originally dated Mike in order to get information but developed feelings for him.
- In Season 5, Mona trusted Mike enough to tell him her plan to try and stop A.
- After the 5-year time jump, their relationship status is unknown.
- In Till DeAth Do Us PArt, Mona is seen kissing a French cop, and that Mike and Mona did actually break up between the time jump.
- Janel Parrish either wants Mike to return in Pretty Little Liars: The Perfectionists, or for her to have a love interest like Mike.