In April 2025, daily Spotify plays of a 22-year-old Japanese album track started climbing. The song was ‘Otsukare SUMMER’ by HALCALI, the Tokyo pop-rap duo of HALCA and YUCALI. Before the spike, it had been pulling around 2,000 to 3,000 plays a day. By April 25th, it had passed 10,000. Then, by April 28th, it was at 40,000. By May 9th, it had reached 148,000.
A year on, the track has passed 6.5 billion TikTok views, more than 150 million total streams across platforms, and charted on Spotify’s now-retired viral charts in 37 countries. It is also nominated for Best Viral Song at MUSIC AWARDS JAPAN 2026, which takes place at TOYOTA ARENA TOKYO on 13th June.
HALCA and YUCALI have also returned to live activity for the first time in over a decade. In August, they’ll play SUMMER SONIC Tokyo on Spotify Stage’s Gacha Pop Live section, appearing alongside yama and NOMELON NOLEMON on the festival’s August 16th line-up.
‘Otsukare SUMMER’ appeared on HALCALI’s 2003 debut album ‘HALCALI BACON’. The track never received a single release, and its first official music video would not arrive until 2025. For more than two decades, it remained an album cut rather than one of the duo’s defining songs.
HALCA and YUCALI had been friends since elementary school, when they attended the same dance school. After winning the spring 2002 FEMALE RAPPER audition, they were taken under the wing of O.T.F (Oshare Track Factory), the production unit of RIP SLYME’s RYO-Z and DJ FUMIYA. That same summer, RIP SLYME brought them on stage at a free Budokan show to perform what would become their debut single, ‘Tandem’, in front of more than 10,000 people.
‘Tandem’ was released in January 2003, before ‘HALCALI BACON’ arrived that September. The album introduced HALCALI as a playful, idiosyncratic pop-rap act, anchored by O.T.F’s production and the duo trading lines with the easy rhythm of two friends chatting after school. It wasn’t an obscure release in Japan, reaching number five on Oricon and remaining on the album chart for 21 weeks.
While O.T.F handled most of the record, including the singles, the remaining tracks were handled by a guest roster sitting at the intersection of Japanese hip-hop and Shibuya-kei — Scha Dara Parr, KOHEI JAPAN of MELLOW YELLOW, hi-posi’s Miho Moribayashi, Nathalie Wise, and the producer of ‘Otsukare SUMMER’, Tomoyuki Tanaka, better known as Fantastic Plastic Machine.
HALCALI’s debut single ‘Tandem’ introduced the duo’s playful pop-rap style ahead of their debut album.
Born in Kyoto and a key figure in late-90s Shibuya-kei, Tanaka brought the movement’s mix of bossa nova, French pop, lounge and club music into ‘Otsukare SUMMER’. He wrote and produced the track, with composition and arrangement credited jointly to him and longtime collaborator Masayuki Kumahara.
HALCA told J-WAVE that she and YUCALI, still in middle school at the time, would head to Tanaka’s Daikanyama studio after school, eating snacks and chatting while they recorded. YUCALI remembered Tanaka’s self-sung demo, still drilled into her memory.
“He was singing this song in this incredibly husky voice (laughs). It’s burned into my mind, I still can’t forget it.”
YUCALI, speaking to J-WAVE
The title ‘Otsukare SUMMER’ is a pun on otsukaresama, a Japanese phrase often used to thank someone for their work or acknowledge their effort. The song turns that phrase into a summer send-off, following a teenage beach crush from playful bravado to an end-of-season comedown. Its hook returns to the image of a young girl secretly crying as her sun-kissed skin cools, while the verses catch the narrator trying to play it cool and asking to be noticed. In 2003, though, none of that made it the obvious hit. It stayed on the album.
The viral movement began outside Japan. HALCALI’s label, FOR LIFE MUSIC, named the United States, the United Kingdom, and Southeast Asia together in its earliest report on the resurgence. Luminate data later traced the earliest US movement to New York, then Los Angeles, Chicago, and Dallas, before the song spread to the Philippines and Mexico. As the wave grew, it also appeared on Spotify viral charts in Malaysia, Thailand, Vietnam, Kazakhstan, Saudi Arabia, the United Arab Emirates, South Korea, and the Philippines.
Inside FOR LIFE MUSIC, the spike was first spotted through data analysis by a new graduate staff member. Digital promotion chief Yuta Kono later told Musicman that the earliest movement had emerged organically overseas, not from anything the label had seeded. Rather than trying to force the buzz internationally, the company focused on bringing it back into Japan, moving to convert unofficial TikTok uploads into official audio sources and building support around the story across streaming platforms and the wider music industry. Kono framed it as turning “accidental buzz into engineered buzz”.
A second wave arrived in July and August 2025, driven partly by a new TikTok sound cut of the song’s “kamatte kamatte” interlude. The label’s own choreography video and influencer outreach had been ready to go, but the breakthrough came from Japanese high-school TikTok duo Hatsuyagi (@hatuyagi), who had independently come up with their own dance for the song. Their video went viral, pushing the song further internationally, while popular J-pop acts including Naniwa Danshi, NiziU, and OCTPATH later joined the TikTok dance trend. Overseas fan edits pairing the track with the anime adaptation of Taizan 5’s childhood trauma-thon Takopi’s Original Sin also contributed to the same wave. By July 26th, ‘Otsukare SUMMER’ had entered Spotify’s Viral 50 – Global chart for the first time, and on August 7th it peaked at number two on Billboard JAPAN’s Japan Songs (US) chart.
Meme traffic isn’t always the best indication of staying power, but Spotify’s data showed listeners were sticking around. Spotify Japan’s Noriko Ashizawa told Billboard JAPAN that more than half of the song’s listeners were under 25, and that more than 70% had saved it to their own playlists or libraries. Spotify also helped carry the song beyond the initial spike, adding ‘Otsukare SUMMER’ to its Gacha Pop playlist in May. The playlist became one of the strongest drivers of the revival, with HALCALI selected for the cover twice.
HALCA and YUCALI never formally announced a hiatus, but HALCALI activity slowed sharply after 2012. Their last widely documented live appearance before the revival was in December 2012 at COUNTDOWN JAPAN 12/13. In the years that followed, both built lives largely outside the group. YUCALI qualified as a nutritionist and launched her catering brand #cali飯 (“cali meshi”), later forming the food-and-music band CAMPS. HALCA moved into photography and exhibition work, and joined Kenji Ozawa’s 2016 touring band on analogue instruments and chorus.
The early viral wave reached them through people from HALCALI’s original label and management circle. HALCA first heard about the revival that spring from their former director and manager, while YUCALI said a manager sent a link to a group LINE chat showing the song was spreading overseas. Both described the situation as strange and hard to fully grasp. HALCA later told Lmaga.jp that she and YUCALI initially talked about it “a bit like it was someone else’s business”, and that the scale only began to feel real when ‘Otsukare SUMMER’ started appearing every time she opened social media.
YUCALI was especially surprised by the song choice. HALCALI already had more obvious entry points for overseas listeners, including anime tie-ins for NARUTO and Eureka Seven.
“We’ve contributed songs to NARUTO and Eureka Seven, so I can understand why those would get people excited. But ‘Otsukare SUMMER’ is just one track from ‘HALCALI BACON’. The fact that people found it, translated the lyrics, and built up this whole wave of excitement around it, it’s like, wow. It really makes you feel that mysterious things can happen.”
YUCALI, speaking to J-WAVE
FOR LIFE MUSIC began uploading archive HALCALI videos to YouTube in May 2025. On September 19th, close to the 22nd anniversary of ‘HALCALI BACON’, ‘Otsukare SUMMER’ received its first official music video. The animated clip was directed by illustrator magoyama, who also handled the character design, background art, and storyboard. By April 2026, the video had passed 20 million views on YouTube.
HALCALI’s first official music video for ‘Otsukare SUMMER‘, released 22 years after the track first appeared on ‘HALCALI BACON’.
2026 saw ‘HALCALI BACON’ released on vinyl for the first time, alongside a CD reissue on February 11th. A new digital ‘Otsukare SUMMER’ EP arrived on March 2nd, featuring the original track with HALCA-only, YUCALI-only, and instrumental versions.
The stage return came in September 2025, when HALCA and YUCALI made a surprise guest appearance during TOKYO No.1 SOUL SET’s set at KOYABU SONIC, the Osaka music-and-comedy festival curated by veteran comedian Chihiro Koyabu. HALCA later said Koyabu had reached out to her personally, and that having Koyabu, RIP SLYME, and Scha Dara Parr around gave her “a sense of reassurance, or comfort”. Asked what comes next, she said nothing was concrete, but that she and YUCALI had agreed on one rule: do it if it sounds fun.
At MUSIC AWARDS JAPAN, ‘Otsukare SUMMER’ is nominated alongside songs from AiScReam, M!LK, CUTIE STREET, and CANDY TUNE in the Best Viral Song category. Five of the six nominees are current idol or idol-adjacent acts. HALCALI stand apart as a pop-rap duo nominated for a track released in 2003, long before the streaming and short-form platforms that revived it existed.
RELATED: MUSIC AWARDS JAPAN 2026 reveals full nominees: Kenshi Yonezu, Fujii Kaze, and HANA among top contenders
TikTok, YouTube, and streaming have already helped older Japanese tracks find listeners outside Japan, from the city pop revival around Mariya Takeuchi’s ‘Plastic Love’ and Miki Matsubara’s ‘Mayonaka no Door / Stay With Me’ to the overseas rediscovery of Jun Togawa’s ‘Suki Suki Daisuki’ and Masayoshi Takanaka‘s catalogue. ‘Otsukare SUMMER’ belongs to that lineage, though its starting point was especially unlikely. The song had no single release, no original video, and none of the built-in overseas recognition of HALCALI’s anime tie-ins.
The MUSIC AWARDS JAPAN 2026 Grand Ceremony takes place on 13th June, with live coverage streaming on YouTube. Whatever the result, a song that spent more than two decades as an album cut will arrive on the ballot with a global audience HALCALI never saw coming.
HALCALI
HALCALI BACON
Release Date: 03/09/2003
Label: FOR LIFE MUSIC ENTERTAINMENT
Stream: Spotify | Apple Music
CD: CDJapan
Vinyl: CDJapan | Black Screen Records
