Vocal Synths in Anime
Anime
This list covers any anime that utilizes vocal synths (VOCALOID, UTAU, CeVIO, Synthesizer-V, etc.) in some sort of way. This mostly focuses on direct usages of vocal synths within the shows, but some of the entries here are attached for more unusual reasons.
Note that I will not be counting song videos for this, nor am I cataloging simple references to Miku (so no Hyouka, for instance). I also may not have everything in-scope listed; these are just the ones I know about. If I'm missing anything, please let me know in a DM!!
The order's a bit messy due to odd overlap areas (thanks, Jashin-chan), but here's the basics and their general order:
-Shows based on Vocaloid song series
-Shows with official, licensed voicebanks
-Shows that utilize vocal synths in-show for non-musical purposes
-Shows with vocal synth characters (i.e., Hatsune Miku)
-Shows with vocal synths used in the music
-Shows that cover vocal synth songs
-Shows that reference vocal synth technology as a plot point
[Note: will update the numbers later. Feel too sick to do so currently.]
Note that I will not be counting song videos for this, nor am I cataloging simple references to Miku (so no Hyouka, for instance). I also may not have everything in-scope listed; these are just the ones I know about. If I'm missing anything, please let me know in a DM!!
The order's a bit messy due to odd overlap areas (thanks, Jashin-chan), but here's the basics and their general order:
-Shows based on Vocaloid song series
-Shows with official, licensed voicebanks
-Shows that utilize vocal synths in-show for non-musical purposes
-Shows with vocal synth characters (i.e., Hatsune Miku)
-Shows with vocal synths used in the music
-Shows that cover vocal synth songs
-Shows that reference vocal synth technology as a plot point
[Note: will update the numbers later. Feel too sick to do so currently.]

TV, 2014,
12 eps
Me:-
Author:6
The show is *heavily* connected to the vocal synth community, as it's basically an alternate continuity adaptation of the Jin's VOCALOID-only song series, Kagerou Project. All episodes are named after one of Kagepro's songs; they all basically adapt and alter the events previously shown within the music videos. Most episodes feature a human-sung cover of the original, but IA still sings "Otsukimi Recital" within the show itself. :D There's also official IA versions of both Daze and Days, the opening theme and the ending theme (respectively) of the show.

TV, 2015,
12 eps
Me:-
Author:7
The OTHER anime adapted from a VOCALOID song series. Much like Mekakucity Actors, Mikagura Gakuen Kumikyoku adapts from Last Note.'s song series of the same name; unlike Mekakucity Actors, I don't remember Mikagura actually having any of the original songs within, instead utilizing human-sung covers.

TV, 2022,
12 eps
Me:-
Author:-
Jashin-chan has grown more and more entwined within the greater vocal synth community as time has gone by.
First, Hatsune Miku herself is a minor character within the show; they even used her voicebank* instead of hiring a human to play her**.
Second, both an insert song and the ending theme use vocal synths. The insert song is a duet between Miku and Jashin, while the ending theme is a duet between KAFU, of CeVIO AI, and KAF.
Third, Jashin-chan herself now has a VOICEPEAK bank herself.
Fourth, they just ran a song contest oriented at vocal synth users, so we're likely to see a human cover of a vocal synth song in the upcoming season.
*I'm pretty sure it's her v4, given both her sound and her outfit design.
**The Spanish dub used a real human to voice her, which is pretty fair, all things considered.
First, Hatsune Miku herself is a minor character within the show; they even used her voicebank* instead of hiring a human to play her**.
Second, both an insert song and the ending theme use vocal synths. The insert song is a duet between Miku and Jashin, while the ending theme is a duet between KAFU, of CeVIO AI, and KAF.
Third, Jashin-chan herself now has a VOICEPEAK bank herself.
Fourth, they just ran a song contest oriented at vocal synth users, so we're likely to see a human cover of a vocal synth song in the upcoming season.
*I'm pretty sure it's her v4, given both her sound and her outfit design.
**The Spanish dub used a real human to voice her, which is pretty fair, all things considered.

TV, 2006,
11 eps
Me:-
Author:-
Yoshida-kun actually has an official VOICEROID bank.

TV, 2017,
13 eps
Me:-
Author:-
The show has two official collaboration vocal synth characters: ROSE, who is voiced by Minato Yukina's actress, and POPY, who is voiced by Toyama Kasumi's actress. They were released into CeVIO AI in 2022 and Synthesizer V AI in 2023.

TV, 1998,
13 eps
Me:-
Author:-
The show uses a PlainTalk voicebank as the episode title card announcer.

TV, 2025,
12 eps
Me:-
Author:-
The system voice uses one of Yuzuki Yukari's A.I.VOICE voicebanks.

ONA, 2023,
6 eps
Me:-
Author:-
Miku is voiced by one of her banks in show. (Probably her v4 again.)

TV, 2018,
76 eps
Me:-
Author:-
Miku is a character in this, albeit voiced by a human (her actual voice provider, Saki Fujita). I don't believe any voicebanks were used within the series.

Movie, 2019,
1 ep
Me:-
Author:-
Miku's back, and even has a song in this one! Note that the song actually uses one of her VOCALOID banks this time. :D

Movie, 2025,
1 ep
Me:-
Author:-
Yes, the "Miku" in that title does indeed refer to Hatsune Miku herself. The trailers (as well as the originating game) indicate that Miku was likely voiced by one of her NT banks.

TV, 2014,
4 eps
Me:-
Author:-
Stars the VOCALOID characters MATCHA and AZUKI. Their voicebanks were not used.

Movie, 2017,
1 ep
Me:-
Author:-
A whole short film based on SSS Goudoukaisha's vocal synth characters (Zundamon, the Tohoku sisters, and the like). Not sure if the actual voicebanks are used or not, since I haven't watched it myself.

Movie, 2006,
1 ep
Me:-
Author:-
This was the first film to utilize a VOCALOID within its soundtrack; you can hear Lola in "The Girl in Byakkoya".

TV, 2006,
23 eps
Me:-
Author:-
A super minor example, but Ergo Proxy utilizes Radiohead's "Paranoid Android" as its ending theme; "Paranoid Android" itself uses Plaintalk for the "I may be paranoid, but not an android" parts.

TV, 2009,
12 eps
Me:-
Author:-
The final ending theme, "Koisora Recycling featuring Mikkuchu Juuchu", is sung by Hatsune Miku.

TV, 2011,
22 eps
Me:-
Author:-
The ending themes used Me and Aw, an unreleased vocal synth duo of an unknown engine. In fact, these ending themes are one of the few ways to hear them, making this show a pretty important piece of vocal synth history.

TV, 2011,
26 eps
Me:-
Author:-
Shockingly enough, English VOCALOID Sweet Ann actually sings all 3 of the "Helvetica Standard" songs, a set of background OST tracks.

ONA, 2011,
2 eps
Me:-
Author:-
The show utilized Edgar Lovecraft's "Prologue to the New World", sung by Miku, as its ending theme.

TV, 2012,
8 eps
Me:-
Author:-
Ultra-famous within the greater Vocaloid scene, Black*Rock Shooter's opening theme features the vocals of Hatsune Miku. I believe this particular part of the franchise uses a remaster of the renowned Supercell song.

TV, 2013,
13 eps
Me:-
Author:-
The ending theme is "Kaikai Emaki" by AVtechNO! and Teniwoha; it utilizes the vocals of Hatsune Miku.

TV, 2013,
12 eps
Me:-
Author:-
"Summer Festival", the ending theme for episode 6, is sung by Hatsune Miku. It's actually a cover of an older, non-vocal synth song.

TV, 2013,
12 eps
Me:-
Author:-
IA sings Ishifuro's "One Two Hello", the main ending theme.

TV, 2014,
13 eps
Me:-
Author:-
The ending theme is Nashimoto Ui's "Shijuuku Nichime"; it utilizes the vocals of Hatsune Miku.
I believe the rest of the franchise has since moved away from synthetic vocals.
I believe the rest of the franchise has since moved away from synthetic vocals.

TV, 2016,
25 eps
Me:-
Author:-
Oh man. This show seems to feature a terrifyingly high amount of vocal synths, if the people trying to figure out who sung what on VocaDB are right. XD
Fun fact: one of its arrangements is in the soundtrack for Guardians of the Galaxy 3, marking Miku's debut in the MCU!
Fun fact: one of its arrangements is in the soundtrack for Guardians of the Galaxy 3, marking Miku's debut in the MCU!

TV, 2017,
25 eps
Me:-
Author:-
New songs, same terrifying amount of voicebanks. Have fun figuring them out! ;3

ONA, 2018,
96 eps
Me:-
Author:-
Luo Tianyi sings the opening theme "Fei Ren Zai" by Dong DianP and Dahenei Hang Tai.

TV, 2019,
12 eps
Me:-
Author:-
Miku sings Yuuya's "INDETERMINATE UNIVERSE", the main ending theme.

TV, 2019,
12 eps
Me:-
Author:-
This is here not for its opening or ending themes, but for an insert song! VOCALOID Gumi is the vocalist for TeishotokuP's "little bunny". Interestingly enough, TeishotokuP is something of a character within the show, too.

TV, 2019,
12 eps
Me:-
Author:-
The ending theme for episodes 1-6 is KanimisoP's "Pippi-Pirikara, Pirikarako.", which utilizes the VOCALOIDs Meika Hime and Meika Mikoto as its vocalists.

ONA, 2020,
12 eps
Me:-
Author:-
Interestingly enough, both the original *and* the dubbed opening theme count here! The original OP is "All Saints Street" by Dahenei Hang Tai and Creuzer, and it uses the VOCALOIDs Luo Tianyi, Yuezheng Ling, Mo Qingxian, and Yanhe. The Japanese dub insteads uses a cover featuring Sato Sasara and Suzuki Tsudumi, both of whom are CeVIO AI banks.
I believe all seasons have had the same themes with no real difference between the sets, so I've only added the first season here so as to save space.
I believe all seasons have had the same themes with no real difference between the sets, so I've only added the first season here so as to save space.

TV, 2023,
12 eps
Me:-
Author:-
The ending theme was once again performed by #kzn, Kizuna AI's CeVIO AI bank.

TV, 2010,
12 eps
Me:-
Author:-
OreImo's a weird but important addition to this list: basically, there were these massive song contests held on NicoNico where winning songs could become one of OreImo's ending themes. Many a Vocaloid song ended up in the show because of that, though they were covered by human singers for the final product.

TV, 2016,
12 eps
Me:-
Author:-
"Kokoro Palette", the ending theme for the finale episode, is actually a human-sung rendition of a VOCALOID song. The original version, sung by GUMI, was instead made to promote the manga.

TV, 2022,
12 eps
Me:-
Author:-
While the opening theme within the show itself is human-sung, "Kaguya" actually has an official Miku version; the latter was even released first.

TV, 2019,
12 eps
Me:-
Author:-
Actors is pretty strange; Crunchyroll describes it as a "Vocaloid x voice actors collaboration", and while VOCALOID (as in, the tool itself) exists for the plot, the show itself features human vocalists. Many of the songs were originally performed by vocal synths, and then covered by utaites.

TV, 2023,
11 eps
Me:-
Author:9
Synthetic vocals are actually a plot point this season! VOCALOID is directly referenced by name, but the synth mentioned is more likely to be a so-vits-svc or Diff-SVC style AI voice converter than a standard voicebank.
Note: I don't actually think the lines were spoken by a vocal synth, so much as just an actor pretending to be one.
Note: I don't actually think the lines were spoken by a vocal synth, so much as just an actor pretending to be one.