This is for all my ex-boyfriends / Listen up / I’m a singer-songwriter! … That’s me, a singer-songwriter / Just because you dumped me / Doesn’t mean my life’s meaningless / Because I’ll put it all together into material for writing.
—“SSW”

I feel the lyrics to “SSW” off her first album under a major label, “KoreColor” (2017), describe Koresawa like nothing else—the way she’s determined to turn every heartbreak into art. It feels less like mere “material” and more a manifesto declaring her secret weapon: that which rings out where her music and personal life join. Koresawa’s pop rock sound rooted in her own reality has helped her engage with listeners all along. Building on the explosive success that her 2024 single “Dear ex-girlfriends” experienced on social media last year, the singer-songwriter’s ready to take another big leap forward.

Koresawa’s dream of becoming a singer may have started out as a faint glimmer when she was young, but it was always undeniably there. Memories of learning to play the piano at two or three years old, singing for an audience, and the compliments she received for her performances naturally fostered her love of music. According to Koresawa, what really strengthened her resolve to become a singer-songwriter was hearing the applause she got for singing aiko’s classic 1999 ballad “Kabutomushi.” That might explain why the minute, everyday details that are so central to her work can make it feel like Koresawa shares a lineage with the legendary singer. Take Koresawa’s 2017 song “Tobacco,” where she weaves longing and resentment through the recurring image of cigarettes, and the signs are all there:

The cigarettes you left behind / They’re my least favorite thing / And yet / Why did I light one? / It had your smell / Your smell
—“Tobacco”

Koresawa went on to be further influenced by YUI, who inspired countless “acoustic kids” after her. In her third year of middle school, Koresawa began pursuing music in earnest with an acoustic guitar she received as a gift from her father. As soon as she entered high school, she joined the band club, where she warmed up to music as a hobby by covering songs by artists like YUI. And while she hadn’t had songwriting on the mind before that, what really pushed her into action was the kind of jealousy and competitive spirit all too familiar to teens.

When a friend in her club came in with their own song, she felt like she had to do better. The anxiety urged her to take action immediately. That’s when she came across a flyer for a contest where entrants write and perform their own songs. In an amazing turn of events that proved how much potential she had, Koresawa advanced to the national level on her very first try. But the joy was short-lived: With absolutely no prior experience performing live, she couldn’t properly showcase her skills at the event. And it was then that she realized, if she was going to pursue her dream, she had to get more serious about it.

After graduating high school, Koresawa moved from Osaka to Tokyo to develop her music career further. From there, she slowly climbed the ladder of fame. She performed to a massive audience at Summer Sonic the following year in the DERENNO!? SAMASONI!? audition-based concert for discovering new talent. She then independently released her de facto debut single, “Yuutsu mo aishite,” in 2014, and her first EP, “Kimi No Band,” which was available nationwide. But what sent her soaring almost overnight was the success of her hit song “Tobacco,” mentioned earlier. Koresawa wrote the song based on her own dating history, documenting all the feelings that come with a breakup and channeling the same energy into the accompanying music video. Listeners empathized with the lyrics and the song spread like wildfire. With around 68 million views on YouTube to date, it’s unquestionably her most recognized song. The song appeared on “KoreColor,” her first album after signing with a major label, and now she was officially in the big leagues.

Another significant aspect of her artistry is her visual representation. When appearing in the media, she dons a mask depicting Reko chan, a character she created with inspiration from Kumamon and Control Bear. Designed in collaboration with illustrator Uchibori Simpe during his indie days, the character is an extension of her identity as an artist, but she only adopts it for media appearances—when she performs live, she interacts with her audience maskless, showing how much thought she puts into connecting with people. If I were allowed to guess, I’d argue her approach is to appear in concert exactly as she is, without any sort of fabrication, while donning an inscrutable, immutable mask in settings where outsiders might otherwise have even the slightest chance to distort her image.

Koresawa’s songs center around their lyrics. She’s stated that her core vision is about “singing cheerfully about feelings girls can’t express outwardly.” She draws from her own experiences and expresses directly those emotions that we’ve all felt but usually find hard to articulate. For instance, she takes complex feelings that can’t be dealt with with a simple “we broke up” or “it’s over” and digs deeper, unpacking them and capturing it all in simple language. Her soft yet resilient vocals are the perfect complement to those everyday details. It’s like a letter tucked away in an old mailbox.

Another key to Koresawa’s music is her strong, positive view of herself. You can hear all throughout her songs how, no matter the pain or adversity she experiences, she stays firm in her belief that they’re ultimately steps toward personal growth and that whatever comes next will bring better times. Take the title track off her album “SSW,” where she sings, “Just because you dumped me / Doesn’t mean my life’s meaningless,” or in the viral single “Dear ex-girlfriends,” where she reflects on how it was her experiences with past relationships and breakups that opened the door for the perfect relationship she has now. Both show her optimistic mindset.

Interestingly, her messages of self-love and positivity align with wider trends led by Gen Z in particular. It’s a trend first seen in 2022 with “Kawaikute gomen” by HoneyWorks and since heard with other popular groups like FRUITS ZIPPER and CUTIE STREET. In some ways, Koresawa was ahead of the curve in capturing the zeitgeist. She wrote the song “saijyoukyuunikawaiino!” for Cho Tokimeki Sendenbu and it’s no coincidence that it went viral on TikTok. With lines like “After you dumped me I’m the cutest ever,” she gets at the very essence of self-love—a theme she’s always explored in her own music.

Her fourth studio album, “To the one who chose me and the one who did not choose me,” came out earlier this year, and balances her existing style while exploring language from fresh perspectives. Tracks like “Don’t Cheat!,” where she uses the Osaka dialect for warmth and vibrancy, or “Meow Meow Meow,” where she cleverly works cat sounds into the lyrics, showcase this experimentation. You can also hear it in songs like “My Life,” with a rhyme and rhythm that border on rap, and “I’m going to be your wife.,” with its vivid depiction of simple, happy married life. Listening to the lyrics calmly and carefully, you begin to realize that the amazing feelings she explores are ones that have always been right under our noses. In fact, they’re the parts of life that are so obvious that we often overlook them or take them for granted. This whole new album feels like it’s taking all those things, wrapping them up in beautiful wrapping paper, and handing them to the listener to make sure they don’t miss out on such moments.

This September, Koresawa will perform on a stage she’s dreamed of since her debut: the Nippon Budokan arena, practically a holy pilgrimage for Japanese musicians. Despite wanting it for so long, she’s admitted she’s still at a point where she feels more anxious about it than excited. Koresawa has always used her music as a way to build a community where she and her fans can heal emotional wounds together. With bigger and bigger venues in her sights, she’s taking pains to hold onto the connections she has now, and it makes it clear that she’s entered a new chapter.

Koresawa’s music is a unique blend of the accessibility of J-pop and the authenticity of indie. Her bright, lively melodies ensure popular appeal, while her lyrics and musical flourishes remain arrestingly honest and full of indie experimentation. The balance of the two is a compelling success story of the harmony between popularity and artistry that’s increasingly valued in the Japanese music scene. With her extraordinary sensibilities, and the way she explores them through universally adored melodies and words, she’s perfectly in step with the era of self-love, and therefore deeply rooted in the taste of mainstream music. Her approach lets her convey the subtle emotions of an ordinary day in detail and awaken listeners to their own everyday lives—and she’s just getting started.