"Mesmerizer" (メズマライザー) is a 2024 song by Japanese music producer 32ki (pronounced "Satsuki") featuring vocals by Vocaloid virtual singer Hatsune Miku and Synthesizer V [ja] Kasane Teto.

[6] The song was included on 32ki's first album, Circus's Detail, which was released during Niconico Chokaigi [ja] 2024.

[8] "Mesmerizer" contains a high-density mix, a rhythmic and hooky sound, and lyrics that leave room for interpretation.

[9] 32ki said that the melody is influenced by "high-speed singing/high range" songs written by such as Japanese music producer Tohma and kemu [ja].

[10] Patrick St. Michel of The Japan Times described the song as "jagged sonic textures — with Jersey club touches buried beneath clattering beats — and tops it off with vocals courtesy of Miku and fellow synthesized character Kasane Teto".

[6] The music video for the song was created by "channel"[a], whose fan-made animation for "Rabbit Hole" by Deco*27 went viral on social media in February 2024.

[6][7] In the music video, Hatsune Miku and Kasane Teto dance to cheerful singing and rhythmic effects, wearing clothing in the style of an American diner.

Teto, although visibly frightened by Miku's transformation, continues to dance with a concerned expression, her eyes losing their pupils and irises changing to a dull red.

[6][7] During the final seconds of the video, although obscured by a shower of confetti, Teto's eyes close momentarily before opening and fading to black, her distressed expression fading to a vacant smile with black eyes like Miku, implying that she also has been hypnotized.

Patrick St. Michel argued that the song "shows how Miku and the software she represents remain vital to the musical ecosystem of the 2020s".

[11] On October 2, 2024, the song was included in Sega's rhythm game Hatsune Miku: Colorful Stage!.