Billboard Japan chatted with Sasane for its monthly series “MONTHLY FEATURE” spotlights artists and works currently making an impact on the scene. The rising 18-year-old artist has been turning heads lately with her debut single, “mosi mosi?”

Since March 2025, Sasane has been posting acoustic guitar cover videos on TikTok, drawing major attention at home and abroad with her distinctive visual sensibility and character. “mosi mosi?” — memorable for its opening line, “Hello, hello, can you hear me?” and its addictive hook, “Denpa, denpa no kai-denpa” — is her first original song, released in April. It’s become a full-blown viral hit, racking up over 3 billion plays on TikTok and topping Billboard Japan’s JAPAN Heatseekers Songs chart (released June 10). She wasted no time following up with her second single in July called “otukare,” which is already generating major buzz on social media.

From childhood dance training to design studies in high school, she’s absorbed a wide range of cultural influences. We asked the budding pop icon how all of that creativity came together into music.

You’ve explored a wide range of creative pursuits like dancing and modeling.

I started dancing when I was six, because of my mom. It was hip-hop, and I loved it. That’s what made me want to show something from within, to express myself.

What part of dancing did you enjoy?

I enjoyed expressing sound through my body and moving however I felt. I kept at it seriously until about my first year of junior high, and even performed at small local recitals. Getting a reaction from people made me happy. So for me, it’s always been about the audience.

Is dance also your earliest music-related memory?

Yes. I loved TLC. I started listening to them because of my dance teacher. There was a playfulness to their music, and dancing to it was fun.

You mainly post acoustic guitar cover videos on TikTok. When did you start playing guitar?

Right when I started posting.

Around March 2025?

Yes. I normally get bored of things easily, but figured if people were watching, I could keep going, so started posting partly as practice.

This might be hard to put into words, but where do you think the line is between getting bored and staying interested?

Hmm, I guess it’s whether it’s fun or not? But like I said, getting a reaction is really important too.

Does communication on social media motivate you as well?

Yes, definitely. Sometimes people send me these really long messages, and I think, “Why would they write all this for someone like me?” It makes me happy.

I heard you studied design in high school.

Yes. I think it’s helped with things like video backgrounds and how I present myself. I love magazines and collect them, and the collages I make from cutting them up are actually the backgrounds in my cover videos. I’m always conscious of making sure that just from seeing the image, people can tell that it’s me.

What made you want to study design?

I’d always loved drawing, but I saw design as something that responds to requests… to people’s needs. I thought if I could do that, I could make the most of my own strengths, so I started studying it.

What experiences or lessons from that time stuck with you?

Basically, you come up with a ton of ideas, like 50 total. Then you pick the best one from there, find the combination that feels interesting. I do the same thing with videos — put out as many ideas as possible, throw away what doesn’t work, keep what does.

How do you decide which ideas to keep?

Whether it excites me or not.

How would you describe your own singing voice?

I’ve always loved singing, but never liked my own voice. When I’d listen back, it sounded higher than I thought it was.

You mean it didn’t feel quite right?

Yes. But now I have people who accept it, so I can accept it myself too. It’s become a strength I can embrace, and I enjoy singing. When I recorded “mosi mosi?” I deliberately brightened things up to emphasize the character. I thought it would be catchier that way.

The line “Hello, hello, can you hear me?” really has that character to it too.

I re-recorded that part so many times. [Laughs]

A lot of your TikTok cover videos start with a spoken comment before you begin singing.

I wanted some kind of hook to get people listening. I’d throw in a line related to the song so people would go, “Oh, it’s this song!” and it ended up working really well.

You’ve covered a wide range of genres. When it came time to make an original, what kind of music did you want to try?

When I sang HALCALI’s “Otsukare SUMMER,” I got a huge response from overseas listeners, and I felt like Shibuya-kei suited my voice. That was one image I had in mind.

“mosi mosi?” was produced by Tamico Mukoda. What kind of creator is she to you?

Her choice of words is so interesting. That’s what drew me to wanting to work with her. She comes out with words I’ve never heard before. She’s incredibly knowledgeable, and I think she’s great.

What does the process of working together on a song look like?

I basically just talk about myself — everyday stuff, all kinds of things.

What words came up during the making of “mosi mosi?”

“Space,” I think. Like, “Sasane, you’re kind of like an alien,” and from there it became, “A denpa song would be great.”

“mosi mosi?” really does pack in those Shibuya-kei and denpa song (an intentionally strange and catchy type of Japanese music) elements. What kind of conversations happened around the sound?

I basically just said, “Please have fun with it.” [Laughs] Also, I wanted a feeling that was nostalgic but new at the same time. When I first heard it, I was so moved, like, “Wow, this is so me,” including the lyrics. The line, “Even if the cat hates me, even if Mom scolds me” actually came from an episode I shared while talking with Ms. Mukoda.

So it’s grounded in something that actually happened.

Yes. I thought it was perfect for my very first song.

How did it feel to see the response when the song first went live on TikTok?

Since I’d only ever done cover videos before, I expected the view count to be way lower than usual. The night it went up, I was too nervous to sleep, but the response was beyond what I expected and it made me really happy.

I thought it was clever how the video starts as if it’s going to be an acoustic cover, just for a moment.

At first I really did plan to start it as an acoustic performance, but then I figured (a video using) the track itself would perform better. Overseas fans were commenting, “Denpa, denpa” too, and I was like, “Wow, it’s really reaching people!”

Did you already have overseas listeners before this?

Quite a few were already watching. I was posting hoping that people all over the world would see it, and even back when I was just doing covers, I’d get comments like, “It’s like she stepped out of an anime.”

You reply to comments pretty casually and often, don’t you?

Yes. That matters to me. I’m just so happy people are watching that I end up replying like we’re friends.

You recently performed live for the first time at a high school in South Korea. What memories did that leave you with?

Even with the language difference, they sang along so much. They made signs for me, gave me all kinds of presents, and it really felt like we connected. It was a lot of fun.

Was that your first time performing in front of people?

Yes, my very first time. I want to do it again! I was so nervous at the start. I kept thinking, “Let’s have fun with this, let’s make it fun for everyone.”

On July 8, you released your second single, “otukare,” which is also already going viral.

I love the phrase, “Anma muri shinasan na” (“Don’t push yourself too hard”). I think it’s nice because it’s not about telling someone to “go for it” or pushing them forward, but a phrase that affirms you, that acknowledges you. I wanted to make a song that could deliver that feeling.

A phrase that acknowledges effort and offers comfort.

Back in high school, on my way home from school, everyone on the train — my classmates, office workers, everyone — looked so truly exhausted. The keyword came from my wanting to tell them, “It’s OK” in a pop way. 

What was your first impression when you heard the demo?

Each section had its own playfulness, and that really clicked with me. It kept shifting and changing. I wanted people to be able to enjoy listening to it without getting bored, and I’d shared that image beforehand too.

What did you focus on during recording?

Recording “mosi mosi?” was really hard. I wanted to bring out that bright, upbeat character, but struggled to produce the vocal tone I had in mind. Because of that experience, I think I was able to get a really good vocal take on “otukare.” This one was more about affirming everything wholeheartedly, and I sang it with a gentle feeling.

It sounds like you found a new side of your voice.

I did. I feel like I finally understood how to use my own voice, in a way.

I imagine there were a lot of moments where you had to face your own singing voice over about a year of covering all kinds of songs.

That’s true. Some people would leave comments like, “I think this song would suit you” and I’d listen to it and discover, “Oh, so this suits me too.”

I’m sure you’ll keep making music going forward. Is there any genre you’d like to try?

I listen to a lot of R&B, but I feel like it doesn’t really suit my voice… But if I keep enjoying singing without losing that sense of character, I think listeners will get it, so I want to keep having fun and never lose that playful spirit.

Any future goals, ambitions, or dreams?

I want to perform live in space! I’ll take everyone to space with me. [Laughs]

—This interview by Takuto Ueda first appeared on Billboard Japan