When Idols Are Reaching For The Stars
Introducing Kasumisou to Stella
The Flower and the Stars
Let’s begin with a touch of poetry.
The name Kasumisou to Stella (かすみ草とステラ) brings together two carefully chosen images. Kasumisou, or baby’s breath, is a small white flower that symbolizes purity and tenderness. Stella, which means "star" in Italian and Latin, suggests dreams, brilliance, and the desire to rise higher.
A quiet little flower and a shining star. The contrast seems to perfectly capture the essence of a Japanese idol, someone humble and grounded who aspires to something greater.
Their official nickname is Kasutera (かすテラ). Yes, just like the Castella sponge cake, a sweet Japanese dessert originally brought over from Portugal. But let's go back to our idols; the sweets can wait.
Kasutera made its official debut on June 6, 2021, as an underground idol group built around a clear concept: “The story of six ordinary girls who, through their idol journey, create a narrative meant to bring you happiness.”
At the time of writing, the group is made up of 12 members:
1st Generation
- Arioka Chihiro (有岡ちひろ) @Kastella_chihi
- Higa Haru (比賀ハル) @Kastella_haru
2nd Generation
- Ishima Misaki (石間実咲) @Kastella_misaki
- Kawana Hikaru (川菜光) @Kastella_hikaru
- Takami Kona (高実心花) @Kastella_cona
- Fukui Hiyori (福井ひより) @Kastella_hiyori
- Honda Kasumi (本田香澄) @Kastella_kasumi
3rd Generation
- Ichikawa Kokoro (市川こころ) @Kastella_kokoro
- Sato Koharu (佐藤心遥) @Kastella_koharu
- Tachibana An (立花杏) @Kastella_ann
- Tsukibashi Yuragi (月橋ゆらぎ) @Kastella_yuragi
- Hanaoka Sumire (花丘すみれ) @Kastella_sumire
The Seed Sower
The group’s producer is Sato Shiori (佐藤栞).
If that name sounds familiar, it should. Shiori was a member of AKB48, performing in Teams 8 and B between 2014 and 2019. After graduating from the group, she turned to producing idols with her own distinct approach: emotional, honest, and carefully structured.
She's also an idol herself and is currently the leader member of Kirameki☆Unforent.
Originally, Kasutera was never meant to exist. The audition titled Kimi to Yume a Kasanaru Basho (君と夢が重なる場所) (Where Your Dream Meets Mine) was intended to form just one group, Setsunateki Anastasia, which has disband in 2022, only one year after their debut. But something shifted when Shiori met the candidates in person.
The audition was initially organized to form one group, Setsunateki Anastasia. But when I saw these girls at the venue, I thought, ‘I want to create another group with a completely different concept.’ That is how their formation was decided, right then and there.
オーディション会場でこのメンバーを見て、『もう1グループ別のコンセプトで作りたい！』と思い、急遽決まりました」とかすみ草とステラの結成秘話を明かした。
Deciding to launch a second group on the spot shows a strong instinct and a sharp eye for potential.
Around her, a solid team quickly formed to help bring the new group to life:
- Shōnen T / Tomohisa Sakō, a well-known composer in the anisong world
- Kamiya Saki, a former member of GANG PARADE, in charge of choreography
- Nao Ueki, a former HKT48 member who now works as the group’s stylist
This was an underground project, but one with serious foundations from the beginning.
First Bloom
Among the group's first songs, one stood out as particularly emblematic: Ao Yori Aoku (青より青く), from the mini-album Boku wa Mada Kimi o Shiranai (僕はまだ君を知らない), released on September 16, 2021. It is also their very first music video.
From that point on, everything began to move faster.
Exactly one year after their debut, on October 3, 2022, Kasutera held their first major solo concert at a well-known venue in Tokyo: Spotify O-EAST.
The following day, October 4, they released both their first full-length album, SWEETS AND POP 1, and their very first physical single, Dai Seishun Hajimemasu ! (大青春はじめます！) (We’re Starting Our Great Youth!).
In the span of just one year, the group showed remarkable growth. Their production quality and sense of direction were so clear that people in the scene began calling them "the Nogizaka46 of the underground."
For an underground group, Kasutera had a very coherent live concept. Their entrance during the overture was original, the songs were well-produced, and the costumes were clean and elegant. Everything felt carefully thought out. The producer and staff clearly knew what they wanted to do with this group.
「アンダーグラウンドのグループなのに、かすてらはライブの世界観がしっかりしていて、オープニングのオーバーチュアからの登場の仕方もオリジナルで、楽曲もよく作り込まれていて、衣装もきれいで清潔感があって…全体的にすごくしっかりまとまっていた。
プロデューサーとスタッフがこのグループで何をしたいか明確に持っていた。」
Petals Falling, Buds Rising
The group’s momentum kept building, and with that came new faces.
On April 24 and 25, 2023, five members of the second generation made their official debut across two consecutive concerts.
Around the same time, the music video for Summer Lost Time Blues (サマーロスタイムブルース) was released.
It focused on this new wave of members and introduced their presence to the public.
On April 5, 2025, three core members from the first generation, Koshiba Miu, Suzumori Haruna, and Watanabe Mona stepped away from the group, saying their goodbyes on stage. A few weeks later, on June 27, Yoshikawa Miku also left.
The third generation was officially revealed on April 11, 2025.
They didn’t have to wait long to step into the spotlight. All of them are featured in the group’s latest music video, Natsu no Shiori (夏のシオリ), which was released on July 4, 2025.
Facing the stars
With 12 members now on stage, Kasumisou to Stella is gradually moving away from its underground roots.
In 2025, the group is becoming an essential name in the independent idol scene.
Their rise in popularity goes hand in hand with continuous improvements in production quality. Music videos are polished, choreography is sharp, and the visual identity is stronger than ever. Everything points upward.
While the future remains unwritten, one thing has not changed: their commitment to delivering songs that make people happy, spread positive vibes, and give courage to everyone who listens. This is their motto, and so far, they live up to it perfectly.
The group will celebrate its fourth anniversary on August 15, 2025, at the Shinagawa Intercity Hall in Tokyo. Happy birthday!
A Sprout That Stood Out (Bonus)
This article exists largely thanks to one of the founding members from the first generation: Arioka Chihiro.
Why? Because on her Instagram, she occasionally posts short videos practicing English with her teacher in an international language school.
The conversations focus on her daily life and, naturally, her work as an idol with Kasutera.
This small detail did not escape the notice of Monsieur Croissant...
These simple clips are unpretentious, yet they quickly gained attention far beyond Japan.
Her most popular video on this topic has now surpassed five million views.
Thank you Chihiro, and we wish you a continued success, both in Japanese and in English.
Support the artist
