On Ordinary Superstar, a track from her self-titled mini-album, Rina Sawayama imagines what it is like to be a famous vlogger, “so far removed from who you really are”. It is just one example of the way that the rising pop star, who has another track called Cyber Stockholm Syndrome, prods our perma-connected culture. True to her lyrics, when we meet for a morning coffee near her home in south London, she puts her phone into airplane mode straight away.

“I’m very strict about that,” she says emphatically. “When I’m with someone, the phone is fucking off. There have been so many studies about what phones do in a social situation, even ones that have the screen facing up, but they’re off – it changes the depth of the conversation.” She laughs and glances down at my own phone, set to record.

However, the singer’s relationship with technology is far from clear cut. “You know how some people take drugs to get inspired? I’ll just spend a ton of time on social media, see how anxious I get, then write about it,” she says. Despite this, a Rina Sawayama song sounds how the internet feels in 2018: a nostalgic pick-and-mix of Max Martin’s 90s hits, 00s dance-pop, 80s synths and even anime theme-tune-worthy rock. The overall effect is somewhere between Mariah Carey and PC Music. One of her most striking tracks, Tunnel Vision, embodies all of this contradiction: a duet with US pop rebel Shamir about social isolation, it was created via email. And then there’s her Tumblr-come-alive look: today, she’s a luminous flash of tangerine hair, baby pink camo hoodie and glittering diamante choker.

Sawayama’s embrace of both the internet and its ills might seem a little strange at first, but hers has been a life spent defying expectations. The warm but laser-focused 27-year-old was raised by a Japanese single mother in north London. She attended a specialist performing arts school as a teenager, where she embraced the likes of Slave 4 U-era Britney, Beyoncé and J-Lo, as well as prominent J-Pop artists such as Namie Amuro and Ayumi Hamasaki. Parental expectations, and her own obvious intelligence, meant Sawayama didn’t go straight into music, though.

Pink and perky: Rina Sawayama in the Cyber Stockholm Syndrome video. Photograph: YouTube

Instead, she studied politics, psychology and sociology at Cambridge. There, she was seen not as a Londoner but an “other”, and encountered bullying. “What I hated was this thing of: ‘Oh, there’s lots of Asian students because they’re rich and they’re international,’” she explains, visibly irritated. “No, they’re there because they fucking work hard and they’re clever. When people found out that I was a home student, they didn’t know what to do. That was the first ever time that I really encountered white privilege and how people viewed me. When I realised that you can work as hard as you want but you will still get knocked down, that was really heartbreaking.”

After graduating, and still rebuilding her confidence, Sawayama reconnected with Asian culture, revisiting the J-Pop she had grown up on, and melding its quirks into the music she was now desperate to produce. Despite City banks trying to tempt her with highly paid roles (“My mum was like: ‘Why the hell are you not taking them?’”), back home in London she did odd jobs as well as modelling for an alternative casting agency set up by a friend - something she continues to do to fund her independent music career. However, a stint working at the Apple Store came to an end when she was fired after appearing in a TV advert for Samsung (“they did a tribunal, I was like, ‘Jesus, just fire me!’”). It was a blessing in disguise, though, spurring her she was spurred on to make a go of music, going from SoundCloud demos to working with experimental producers including Clarence Clarity in the space of two years.

With her songs attracting attention both for an unabashed appreciation of the past and a futuristic glow, Sawayama is on the up, and – a few days before we meet – announces her biggest headline show to date. Despite this, she remains – by choice – unsigned, and continues to engage with tough topics such as her own mental health. On the synth-led, part-spoken 10 20 40, about her experience taking SSRIs, she chooses a moving car as a literal vehicle for her message. “The metaphor is about teetering on the edge, but also the romance of driving,” she explains. “And the romance of taking Citalopram or being depressed in the media, when actually it’s so mundane. It’s a daily chore”. There’s also the question of mental health, race and the fact that the UK has never had a mainstream Japanese pop star.

“I think I definitely want to release an album that is meaningful to [that], but once I’ve figured out what it means to be east Asian in a western world,” she says. “It’s a lot of pressure.” In any case, she’s clear on the stereotype she’s most looking to destabilise: that of Asian women as alternately submissive or “fiery dragon ladies”.

Our interview ends, and Sawayama’s relationship with the real and the unreal appears clearer. She turns airplane mode off, and the complicated bond resumes.

Rina Sawayama’s mini album Rina is out now. She plays the Borderline, W1, 28 Mar