🎤✕🤘 The songwriter behind Jujutsu Kaisen's hit "Ao no Sumika" has joined forces with the metal dance unit that just made Billboard history. Kitani Tatsuya and BABYMETAL — two artists who seem worlds apart — have come together for the opening theme of anime Hell's Paradise Season 2. With a CD release now confirmed, here's why "Kasuka na Hana" is one of the most talked-about collaborations in Japan right now.
What Is "Kasuka na Hana"?
On January 12, 2026, singer-songwriter Kitani Tatsuya released a new digital single titled "Kasuka na Hana" (meaning "A Faint Flower") featuring BABYMETAL. The song serves as the opening theme for Season 2 of the TV anime Hell's Paradise (Jigokuraku), which airs on TV Tokyo and other networks.
Hell's Paradise is based on the popular manga by Yuji Kaku, serialized on Shueisha's Shonen Jump+ app, with over 6.4 million copies in circulation. The story follows Gabimaru, a legendary ninja who becomes entangled in deadly battles on a mysterious island — a tale of survival, beauty, and the blurred line between life and death. The anime is produced by MAPPA, the acclaimed studio behind Jujutsu Kaisen and Attack on Titan: The Final Season.
On February 6, 2026, it was announced that the song would receive a physical CD release on March 11. Two editions will be available: a Limited Production Edition (approximately $20) and a Standard Edition (approximately $10). The limited edition comes in an LP-sized package with a specially commissioned illustration of the anime's protagonists, Gabimaru and Yui, depicted in a tender, ethereal scene. A Blu-ray disc featuring the creditless opening movie is also included.
The CD features four tracks: the title song, a "BABYMETAL-less Ver." (with BABYMETAL's vocals removed), a "Tatsuya Kitani-less Ver." (with Kitani's vocals removed), and an instrumental version — allowing fans to appreciate each artist's contribution individually.
Two Worlds Collide: Why This Pairing Matters
To understand why this collaboration has generated such excitement, you need to know both artists' journeys.
Kitani Tatsuya, born in 1996, began posting original music online around 2014 and quickly gained recognition for his exceptional songwriting talent. His breakthrough came in 2023 with "Ao no Sumika," the opening theme for Jujutsu Kaisen's "Hidden Inventory" arc. The song surpassed 100 million streams within three months of release and earned him a debut appearance on NHK's prestigious Kohaku Uta Gassen, Japan's most-watched New Year's Eve music broadcast. He has written songs for artists ranging from WEST. to Hoshimachi Suisei and LiSA, and even formed the unit "GEMN" with actor-singer Kento Nakajima. Two new albums, "DEKAI" and "PURE," are planned for simultaneous release in fall 2026.
BABYMETAL, consisting of SU-METAL, MOAMETAL, and MOMOMETAL, has been redefining musical boundaries since their formation in 2010. Their unique fusion of metal and J-Pop has captivated audiences worldwide. In 2016, their album "METAL RESISTANCE" broke into the US Billboard Top 40 — the first Japanese artist to achieve this in 53 years. They became the first Japanese act to headline London's Wembley Arena and sold out two nights at Tokyo Dome, drawing 110,000 fans.
In 2025, BABYMETAL established BABYMETAL WORLD LLC in the United States and signed a historic global partnership with Capitol Records — becoming the first Japanese artist to secure a frontline deal with the legendary label. Their fourth album, "METAL FORTH," released in August 2025, achieved another first: entering the US Billboard Albums chart Top 10, a milestone never before reached by a Japanese group. The album features collaborations with an international roster including Poppy, Spiritbox, Tom Morello, Electric Callboy, Polyphia, and Slaughter to Prevail.
Against this backdrop, "Kasuka na Hana" represents something genuinely new for both artists. For BABYMETAL, who typically collaborate with metal and heavy rock acts, working with a J-Pop singer-songwriter is uncharted territory. SU-METAL acknowledged this directly, saying: "We usually collaborate with metal bands, so having Kitani Tatsuya bring out a new side of BABYMETAL through this collaboration makes us truly happy."
Kitani described the song's inspiration: "A flower that holds both the strength to root in the earth and the fragility to sway in the wind, standing unmoved as it should be. A person who accepts uncertainty and realizes themselves while living through that uncertainty. I created this song with a yearning for such a 'faint flower' — modest yet dignified, an ideal form."
The Global Power of Anime Theme Songs
Anime theme songs — or "anime tie-ups" as they're known in the Japanese music industry — have become one of the most powerful promotional channels in the country's music landscape.
The evidence is everywhere. LiSA's "Gurenge" (Demon Slayer), YOASOBI's "Idol" (Oshi no Ko), and Kitani's own "Ao no Sumika" (Jujutsu Kaisen) all transcended borders alongside their respective anime, achieving explosive global success. These songs don't just accompany shows — they become cultural phenomena in their own right, driving streams, concert ticket sales, and brand recognition across continents.
Hell's Paradise Season 1, which aired in 2023, was already well-received internationally, with MAPPA's stunning animation and the series' dark, uniquely Japanese fantasy aesthetic capturing overseas viewers through platforms like Crunchyroll.
Now, with Kitani Tatsuya and BABYMETAL each bringing their own established international fanbases, "Kasuka na Hana" sits at a unique intersection. Anime fans, J-Pop fans, and metal fans — three communities that rarely overlap — are finding common ground through a single song. It's a striking example of how Japanese popular culture continues to create unexpected connections.
BABYMETAL's global reach is staggering: from 2024 to 2025, they performed 51 shows across 22 countries, drawing approximately 1.01 million fans. They became the first Japanese group to headline London's O2 Arena (sold out) and performed at The Theatre at Madison Square Garden. They've also opened for Lady Gaga, Metallica, Red Hot Chili Peppers, and Avenged Sevenfold. Their participation in an anime opening theme adds a new dimension to what "anime tie-ups" can achieve.
A Festival Stage Shared
The connection between Kitani and BABYMETAL extends beyond this single release. Kitani was announced as part of the first wave of artists for SUMMER SONIC 2026, alongside THE STROKES, L'Arc-en-Ciel, David Byrne, and JAMIROQUAI. BABYMETAL, long a fixture at international music festivals, continues to expand their presence on both Japanese and global festival circuits.
Kitani has a busy schedule ahead, including his self-produced event "Hugs Vol.6" in July with Eve, amazarashi, and SILICA GEL, plus two albums dropping in fall 2026. BABYMETAL, celebrating their 15th anniversary, is rolling out various commemorative projects, including a book version of their radio show "BABYMETAL no Metaraji!"
A New Chapter for Japanese Music's Global Reach
"Kasuka na Hana" represents something larger than one song. It's a snapshot of where Japanese music stands today — a landscape where genre walls are dissolving, where a singer-songwriter and a metal dance unit can create something beautiful together, where an anime adaptation of a shonen manga becomes the vehicle that carries their collaboration to millions of listeners worldwide.
SU-METAL's reflection captures it perfectly: "When I heard this song, I felt that a flower blooming with quiet dignity taught me the preciousness and beauty of simply existing as yourself."
In Japan, these kinds of cross-genre collaborations are becoming increasingly common, reaching global audiences through the powerful channel of anime tie-ups. In your country, how are collaborations between artists from different genres received? Have you ever discovered new music through an anime theme song? We'd love to hear your experience.
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Reactions in Japan
Got goosebumps the moment Kasuka na Hana played in the OP. The way Kitani's delicate vocals alternate with SU-METAL's powerful voice is absolutely incredible.
Honestly, when I first heard about BABYMETAL x Kitani Tatsuya I was like '???' but after hearing the song, I completely changed my mind. Genius.
The limited edition jacket art of Gabimaru and Yui is so beautiful it makes me tear up. So happy it's a newly drawn illustration. Pre-ordered immediately.
BABYMETAL doing an anime OP was unexpected, but the match between Hell's Paradise's world and metal makes total sense. Metal fits dark Japanese fantasy perfectly.
Having both a BABYMETAL-less ver. and a Kitani-less ver. on the CD is the best. Being able to listen to each vocal separately is such a luxury.
Isn't ¥2,985 (about $20) cheap for the limited edition? Comes with Blu-ray and original jacket art. Very reasonable compared to recent anime merchandise prices.
Kitani Tatsuya — first Jujutsu Kaisen, now Hell's Paradise. This guy's batting average with anime tie-ups is insane.
SU-METAL's comment is lovely. The phrase 'a small happiness you want to protect' is so characteristically her. Love it.
The Hell's Paradise OP animation and the atmosphere of Kasuka na Hana are a perfect match. The combo of petal-scattering visuals with metal sound is insanely cool.
BABYMETAL right now: signed with Capitol Records, hit Billboard Top 10, AND doing anime OPs. Their range of activities is so wide I can't keep up lol
Honestly I was like 'who buys CDs anymore?' but seeing this limited edition package triggered my collector instincts... It works as anime merch too.
Kitani's lyrics overlap so much with Gabimaru's way of living that I almost cry every time I listen. 'A flower that exists as it should' IS Gabimaru.
As a BABYMETAL fan (we call ourselves 'mates'), the best thing is gaining new fans through anime. The overseas reaction has been incredible too.
S1's OP was good too, but this S2 collab is on another level. This might be the most extravagant OP for a Shonen Jump+ adaptation ever.
Personally I wish the BABYMETAL metal element was a bit stronger. But maybe it's well-balanced for an anime OP.
Kitani's also at Summer Sonic this year, his momentum keeps building. Same thing happened after Jujutsu Kaisen — his post-anime-tie-up career surge is wild.
BABYMETAL doing an anime OP feels like a dream. As someone who attended their O2 Arena show, I love this unexpected direction. I've been following Hell's Paradise since the manga too, so double the excitement.
I loved Kitani's 'Ao no Sumika' so I checked out his new anime tie-up immediately. The BABYMETAL collab was unexpected but the song is amazing. I love how Japanese artists don't care about genre boundaries.
From Mexico — I became a BABYMETAL fan through their Latin American tour. I hope anime like this helps more people discover Japan's rock/metal scene.
French anime fan here. I love Hell's Paradise's Japanese dark fantasy setting. It's wonderful how Japanese anime OPs are high-quality songs that stand on their own, not just background music.
BABYMETAL has lots of fans in Korea too. Doing an anime collab after signing with Capitol Records shows they're truly going beyond metal.
As a German metal fan I was skeptical about an anime OP at first, but SU-METAL's vocal prowess really shines through. The coexistence of J-Pop melodic beauty and metal power is undeniable.
The limited edition being LP-sized is a cool touch. Japan's commitment to physical media is alive and well even in the streaming era. Definitely appeals to the collector in me.
From India here. BABYMETAL collabed with Bloodywood before, and now a J-Pop artist for an anime OP. Their cross-genre work genuinely feels global.
Swedish metalhead here. I loved the Spiritbox collab on METAL FORTH but this is a completely different flavor and it's refreshing. Their artistic range is impressive.
Being honest, I feel like BABYMETAL is leaning too pop. I preferred the heaviness of METAL FORTH. The anime OP feels a bit light. But SU-METAL's voice is fantastic as always.
Japanese-American here. It's not rare anymore for Japanese anime theme songs to chart on Spotify globally. I think this song has that potential too, given how broad both artists' fanbases are.
From Brazil. BABYMETAL's São Paulo show was incredible. I learned about Hell's Paradise for the first time through this collab and just started watching. The synergy between anime and music is truly amazing.
This song is a hot topic in the Russian anime community too. Cross-genre collabs are common in the West, but achieving this level through an anime OP is uniquely Japanese.
Having separate vocal versions on the CD is wonderfully nerdy in the best way. Perfect for anyone who wants to really compare each artist's voice closely.
Fan from Taiwan here. Hell's Paradise is popular in Taiwan too, so I'm glad the OP theme is getting attention. I hope BABYMETAL will do a show in Taiwan someday.