In the year and a bit since Heartstopper launched on Netflix, it has not only become one of the streaming service’s most popular shows, but it’s made overnight stars out of its previously unknown cast.

But if you’re wondering what it took to bring the LGBTQ+ coming-of-age drama – which recently returned for its second series – to our screens, we’ve done some digging to find out the secrets from behind the scenes…

Because she wanted to ensure the show was cast authentically to celebrate “all kinds of different queer experiences”, getting the right people to play Charlie, Nick and the other characters took its time.

“We wanted a trans actor to play Elle, we wanted the actors to be around the right age and obviously, there needs to be talented actors as well,” she told the PA news agency.

“So there were a lot of different factors, which made it a really stressful process, particularly trying to find authentic actors.

“If we didn’t find the people we knew the show just wouldn’t work. But we were determined to do it anyway. And we were lucky. We found the perfect people.”

Joe was cast as Charlie in the show after responding to an open casting call, to which 10,000 auditioned.

“You didn’t need an agent, you just sent in a self-tape,” he told This Morning. “I ended up getting the part and it was just all my dreams come true.”

He explained: “I was on my own in my house on the Isle of Man and it was during Covid last year. So I had to fly to London for an audition and then fly home and isolate on my own for two weeks in my house.

“So I was on my own and my agent phoned me and told me I’d got the job and it was just me and my dog in the house. I screamed very loudly.”

While Kit said he knew he didn’t fit Charlie’s physical description, he wanted to go for the role because he loved it so much.

He told Radio Times: “The audition tape they sent through was one of Charlie’s speeches where he’s really just at his most genuine, most stripped back point and it’s really beautifully written, and I thought, ‘I really want to do this.’

“I thought, ‘There’s no chance I’m going to get it,’ because physically there’s nothing about me that could fit this character. But then luckily there was Nick that I could sort of slot into quite well.”

Speaking to Still Watching Netflix, Kit explained: “I’ve always had a baby face, a really bad baby face. When we got cast, they had my picture from when I was about 14/15 in the make-up room. Apparently, the whole make-up team was like, ‘I don’t think you cast the right person? He’s really young.’”

Netflix brought LGBTQ+ rights charity Stonewall on board to help advise and educate everyone involved in the project on topics such as queer history and pronouns, Yasmin Finney, who plays Elle, told Elle magazine.

“I already knew Heartstopper would be queer positive and celebrate chosen family, but I was so grateful of Stonewall’s involvement,” she added.

Jeffrey Ingold, the show’s LGBTQ+ consultant, said in a behind-the-scenes video interview for Netflix: “We can help give a more authentic view of the context in which the show is happening, so it doesn’t feel like a drama that is happening over here, it is based in the reality of what kids are going through.

“We did a lot of conversation and training around what is happening in schools these days, so particularly for the cast, they could take that into the roles, and for the crew, they could also understand why this show matters and what it’s going to mean to the audience who watch it.”

Executive producer Patrick Walters added that Stonewall helped read through scripts and trained everyone on appropriate language and how to cultivate a safe space.

In a behind-the-scenes video interview for Netflix, director Euros Lyn said: “You tell a story as a director, you are not by yourself, you’re really on a huge team of designers, photographers, make-up, hair – loads of people. And I wanted as many of those people as possible to be from the LGBTQ+ communities, so they could bring their experiences and identify the bits of the story that can only be from an LGBTQ perspective.”

“I like to think of it in that the TV show is an expanded version of the comic,” Alice Oseman told Netflix in a video interview.

“The core story of the comic is very much in the show, we haven’t changed what is in the comic, we’ve just made the story bigger and we’ve made the world wider. Beyond Nick and Charlie’s story, we learn a lot more about Tao and Elle, Tara and Darcey and there are also new characters as well.”

She continued: “The thing I’ve learned about adaptations is that something that works for one thing like a comic might not work for a TV show. So when developing Heartstopper as a TV show, we had to look at it from a TV perspective and how do we take this story and make it work on screen.”

9. Alice only tried to get Olivia Colman on a punt and was “shocked” when she said yes

Talking about casting the Oscar-winner as Nick’s mum, she told the PA news agency: “I was shocked. When we were discussing trying to get a big name to be Nick’s mum, I was literally like, there’s no way this is going to happen.

“This is the silliest idea ever and there’s literally not any point doing this. But we tried anyway and Olivia wanted to do it, and I just couldn’t believe it.

“There’s really no other way to say it, I was just shocked but so, so happy, because she’s such an incredible actress, she brings so much to that character, and all the scenes with Nick’s mum just feel so special and subtle and just really beautiful performance.”

“She seemed to really enjoy it,” Alice told PA. “She was only on set for two days and to be honest, I didn’t really get to talk to her very much because we’re on set and it’s very intense.

“But I feel like she really loved the story and she really connected with Kit, who plays Nick, and just really enjoyed working with him.”

While reading through the touching moment in which Nick comes out to his mother as bisexual, Olivia became tearful for real, which initially proved to be a bit of a worry for Kit.

He told This Morning: “Normally before every scene we read it through about 50%, you don’t go 100% of the way. We were reading it through and suddenly Olivia just started crying.

“At first, I was thinking, ’God, she’s just really good, I need to step up my game massively here,′ so I was really worried at that point. I think then other people told me afterwards that it was because it’s such a beautifully written scene and a crucial part in so many people’s lives. I think it really touched her.

“I was just scared to be honest,” he joked, describing her as “the most absolutely lovely person in the world”.

As Joe did not share any scenes with Olivia on the show, he was keen to meet the star, and gave up tickets to the West End production of Les Miserables so he could travel back to set on his day off and meet her.

Kit explained to Still Watching Netflix: “I had two days filming with Olivia. It was originally meant to be Olivia and I filming for two days, and on the second day, I think Joe was like, ‘I would like to meet her, obviously’, so they ended up scheduling some time…”

“That’s not what happened!” Joe contested. “I wasn’t supposed to meet her and then I got a call on the second day saying that we might have to do some pick-ups and reshoots of just before the rain scene in the hallway, so you’ll get to meet Olivia.’ So I was like, if that gets to happen, amazing. And then they called me at like 3pm, asking if I could come in.’

Stephen Fry also has an unexpected role in the show – not that you will have seen him.

The actor lends his voice to the character of Headmaster Barnes, who runs Truham Grammar School where Nick and Charlie go, and can be heard commentating over the tannoy on the school sports day.

He told Attitude magazine: “I had to ask the extras to slow down because I was supposed to be this incredible runner and every take, they were just slowly getting closer to me. I was like, ‘Can you guys just like slow down a bit?’, which was very embarrassing.”

Kit revealed he would often make light of Joe’s love of coffee after filming a kissing scene.

“He had this joke that my breath always smelt of coffee,” Joe told Still Watching Netflix.

“Joe loves coffee and there was this one time where we had to do a practice kiss for a scene and Joe had just had a full cup of coffee and I was just like, this is not nice,” Kit recalled.

“I felt that I was a victim in that situation,” he joked.

Kit had only played rugby as a young child before being cast as star rugby player Nick.

Speaking to Still Watching Netflix, Kit explained that he worked on his game with a coach before and during filming to help him improve.

Joe did go along with Kit for one rugby training session, but “not any more after that”.

“I think he quickly decided that wasn’t for him,” Kit said.

“I didn’t own any sports clothes, so I arrived in loose jeans… It wasn’t rugby,” Joe said.

“I made the executive decision that Charlie wasn’t supposed to be good at rugby, therefore I was allowed to be bad.”

In the season one episode where school bully Harry throws a birthday party, scenes were shot at Hampton Court House, a school in East Molesey.

However, while the party was set at night, it had to be filmed during the day, which the crew had to work around.

Cinematographer Diana Olifirova told IBC: “I loved the windows and had planned to shoot a moonlight effect through them. But we didn’t have access to the location at night. That meant we had to black out the windows, but we lit it to appear as if there were some light outside.

“The biggest challenge in a room full of people was having the camera pick out our main characters. This involved a little planning about where the camera would be so that the actors would hit a mark and we’d have a pre-set light trained on them.”

If you didn’t know that Heartstopper was based on graphic novels of the same name, you probably would have wondered where all the animated moments in the show came from.

All the leaves, lightening bolts and other little animated details all honour Alice Oseman’s original text, which executive producer Patrick Walters told Pink News became known as “Heartstopper moments” to the crew.

“Hopefully it gives you goosebumps and makes you lean in when those moments happen,” he said.

The writer and creator made a blink-and-you’ll miss it appearance in episode eight of season one, seen as a passenger on the train that Charlie and Nick travel to the seaside on.

She revealed on Twitter that she was even drawing the comic versions of the characters from her graphic novels during the scene.

Alice said she “honestly didn’t know anything about TV making before” adapting Heartstopper. “I have never been on a TV set before,” she said in a Netflix video interview.

However, she said she was on set “every day” during the shoot, overseeing everything that was happening.

“I have learned so much about what everyone on set does, all the different roles that there are, and it really is a team effort,” she added.

Executive producer Patrick Walters told Pink News: “We decided we wanted the show to speak to as many different ages as possible, so we were deliberate about not having too many swear words, too many overtly adult situations, because that stuff didn’t fit the tone of the show anyway. But also in not having that, we were opening up the show for more people to see it.

“I really hope the younger generation, 11, 12, 13, will watch the show and get something out of it.”

There’s an Easter Egg in season two’s second episode that makes reference to Joe Locke’s casting in the Marvel Cinematic Universe, ahead of his appearance in Disney+ series Agatha: Coven of Chaos.

After nodding off on Nick’s chest, Charlie says: “Did I fall asleep?”

Nick then replies: “Are you tired or is this movie just really boring?”

“I did warn you I’m not a fan of Marvel movies,” Charlie says.

In an interview with Variety, Joe previously shared his casting hopes for one particularly inspired guest star.

“Jennifer Coolidge should play my grandmother,” he said. “That would be so cool. I love her. She’s amazing.”

Heartstopper is available to stream on Netflix now.