風真いろは (Kazama Iroha) of 秘密結社holoX (Secret Society holoX) just dropped 風向きエントロピー (Kazamuki Entropy / Wind Direction Entropy), and it’s the kind of original song that feels completely, specifically hers. Written, composed, and arranged by 40mP (40㍎P). MV by KANAURU. 43,000 views on release day. This one’s special.

風向きエントロピー: The Sound and What 40mP Built

40mP (40㎥P) is one of the most celebrated Vocaloid producers in the scene’s history — he holds the record for the most songs to enter the Hall of Fame with 76 works, and his most popular songs *カラクリピエロ (Karakuri Pierrot)* and *恋愛裁判 (Ren’ai Saiban)* have each surpassed 10 million views. He’s a songwriter with a gift for melodic simplicity that carries real emotional weight — and 風向きエントロピー (Kazamuki Entropy) is a perfect example of that. The arrangement is warm and airy — acoustic guitar from [TEST], bass from Kei Nakamura, drums from 裕木レオン (Yuki Leon), all other instruments and programming by 40mP himself. It has a gentle, open-sky quality that matches the song’s imagery and themes exactly. Nothing feels cluttered or rushed. It breathes.

The Lyrics and What They Mean for Iroha

The full lyrics are in the description, and they’re worth reading. 風向きエントロピー (Kazamuki Entropy) is a song about growing up in the company of something you didn’t notice was always there — the wind as a metaphor for direction, change, and the unknown. The chorus — “方向なんてまだわからないけど / ただ風の吹くままに” (“I still don’t know which direction / I’m just going the way the wind blows”) — is a simple, quietly profound statement about moving forward without needing to have it all figured out. For 風真いろは (Kazama Iroha), whose name literally contains the kanji for wind (風), it couldn’t fit more naturally. The song feels written for her in a way that goes beyond just being commissioned from a great producer.

Iroha’s Vocal Performance on 風向きエントロピー

Iroha’s voice has a clear, earnest quality that suits this kind of introspective material well. She doesn’t oversell the emotional moments — she lets 40mP’s melodies do the heavy lifting and delivers her lines with a sincerity that lands. The mix by 檜谷瞬六 (Hinotani Shunroku) keeps everything balanced and close, with the vocal sitting naturally in the centre of the arrangement. It sounds like someone genuinely moved by the song they’re singing — which, from everything Iroha has said about her music, she probably was.

KANAURU’s MV and Why This Release Matters

The MV is by KANAURU — one of the most respected names in hololive music video production — and it delivers the kind of polished, emotionally resonant visuals that this song deserves. Subtitle translations in nine languages were prepared for release, which speaks to how seriously this was positioned as a proper worldwide release, not just a domestic drop.

風真いろは (Kazama Iroha) is the fifth and final member of 秘密結社holoX (Secret Society holoX), hololive’s 6th generation, and she has been building her music catalogue steadily since debut. Getting 40mP to write you a song that’s both lyrically and conceptually matched to who you are — and then having KANAURU bring it to life visually — is a big deal. 風向きエントロピー (Kazamuki Entropy) is the kind of release that stays with you.

Track Credits

• Title: 風向きエントロピー (Kazamuki Entropy)
• Vocals: 風真いろは (Kazama Iroha)
• Lyrics / Music / Arrangement: 40mP (40㍎P)
• Guitars: [TEST]
• Bass: Kei Nakamura
• Drums: 裕木レオン (Yuki Leon)
• All Other Instruments & Programming: 40mP
• Mix: 檜谷瞬六 (Hinotani Shunroku)
• MV: KANAURU
• Label: hololive / Cover Corp
• Released: June 18, 2026

▶ Watch: 風真いろは (Kazama Iroha) — 風向きエントロピー (Kazamuki Entropy) (Official MV) on YouTube