What does the number in front of the letters mean?

It is a platform-side identifier for the series, not part of the series name and not a maker code in the studio sense. The same series is sometimes listed with and sometimes without it.

Are amateur series codes studio codes?

They behave like them — a stable prefix with a serial scoped to it — but the prefix identifies a series concept rather than a production label, and several series can share one operator.

Why do these codes reach four and five digits?

Because a long-running series publishes continuously under one prefix instead of retiring it, so the serial keeps climbing where a studio line would have rotated to a new prefix.

How Amateur and Planning-Series Codes Work

Amateur and planning-series releases are numbered by series rather than by studio, producing codes such as 259LUXU-1234 where a numeric platform identifier precedes the series tag and a serial follows it. That serial counts entries published in the series, not products issued by a production label, which is why the numbers climb far higher.

Amateur and planning-series releases are numbered by series, not by studio. The typical shape is 259LUXU-1234: a numeric platform identifier, a series tag, then a serial counting entries in that series. The serial says how many episodes the series has published, not how many products a label has issued.

That difference matters because the mental model people bring from studio codes — prefix means company, serial means catalogue position — is only half right here. The prefix means format, and the company behind it is often invisible in the code.

What are the parts of a series code?

Three parts, and the first one confuses almost everybody.

Part	Example	What it is
Numeric platform ID	`259`	A listing-side identifier for the series
Series tag	`LUXU`	The series' own short name
Serial	`1234`	Position within the series

The leading digits are not a maker code in the way a studio prefix is. They are an identifier assigned by the platform that lists the series, which is why the same series appears in some places as 259LUXU-1234 and in others as simply LUXU-1234. Both refer to the same entry; one includes the listing identifier and one does not.

Practical consequence: when a series code fails to resolve, try it both with and without the leading digits before concluding the code is wrong.

Which series codes are you most likely to encounter?

A handful of long-running series account for most of what circulates.

Code shape	Series	Format
`SIRO-1234`	Shirouto TV	Amateur interview format
`200GANA-1234`	Nanpa TV	Street-casting format
`259LUXU-1234`	Luxu TV	Amateur interview format
`300MIUM-1234`	MIUM	Amateur format
`261ARA-1234`	ARA	Amateur format

Deliberately omitted: which company owns which series. These are widely attributed to a single affiliated network, but we could not read a maker field for any of them — they are absent from FANZA's catalogue, and the storefront that does list them was not reachable when we checked. Rather than repeat an attribution we cannot open and verify, we leave the row blank. The studio code reference applies the same rule to label prefixes.

How do planning-series codes from studios differ?

Planning series issued by established studios keep the normal studio shape but behave like series: one prefix, one recurring format, a very long run of numbers.

Prefix	Character	Status
`SDMU`	Long-running SOD planning line	Closed at 999 in Dec 2022; continues as `SDMUA`
`NHDTB`	Natural High planning line	Closed at 999 in Dec 2024; continues as `NHDTC`
`DVDMS`	Deep's planning line	Closed at 999 in Aug 2022; Deep's now numbers `DVMM`
`RCTD`	ROCKET planning line	Still receiving numbers

Status checked against FANZA product records and the makers' own release listings, 2026-08-03. Three of the four hit exactly 999 and rolled over, which is the same ceiling the single-performer lines run into — the difference is only how long it takes to get there.

The tell is the serial. A single-performer studio line typically rotates to a new prefix in the low hundreds; a planning series runs on for many hundreds or thousands of entries under one prefix, because the concept rather than the performer is the product, and the concept does not need a refresh.

Why do series serials climb so much higher?

Because the prefix is tied to a format that keeps producing, rather than to a line that gets rebranded.

Studio prefixes rotate for marketing reasons — a new production standard, a new line identity, a refresh. Each rotation resets the serial. A series has no equivalent event: LUXU episode 1400 is the same proposition as episode 400, just later. Nothing triggers a reset, so the number simply accumulates.

This gives you a rough diagnostic. A four-digit serial attached to an unfamiliar prefix is more likely a series than a studio line, and a serial in the low hundreds attached to an unfamiliar prefix is more likely a studio line.

What metadata can you expect from a series release?

Less than from a studio release, and structured differently.

Field	Studio release	Series release
Performer credited by name	Usually	Often not, or a first name only
Fixed runtime conventions	Yes	Varies by episode
Cover art format	Standardised per label	Standardised per series
Cast searchable in catalogues	Usually	Frequently not

The performer field is the one that matters for lookups. Amateur-format series frequently credit a given name only, or a name used for that episode alone, so searching by performer often does not work even when the release itself is listed. Text search fails not because the entry is missing, but because the field you would search on was never populated.

That gap is precisely where image-based identification does work, since it does not depend on anyone having typed a name.

How should you search a series code?

Preserve the exact string first, then try the variants in order.

As written — 259LUXU-1234, including the leading digits
Without the numeric prefix — LUXU-1234
Without the hyphen — 259LUXU1234, which some listings use
Series name plus serial as separate terms, if exact match keeps failing

Do not strip the numeric prefix as if it were noise, the way you would strip a site tag. It is part of a legitimate listing convention, and it is sometimes the only form a given index holds. Other failure modes are covered in JAV code not found.

What do you do when the performer is not credited at all?

Match the face, since that is the identifier the release did not omit.

Uncredited or single-name credits are the norm in amateur formats, which makes text search structurally unable to answer "who is this?" Face matching does not depend on the credit: our index encodes faces as 512-dimension ArcFace vectors and compares them across 241,792 indexed faces and 2,333 named performers (our index, 2026-08 snapshot), at a 0.40 similarity threshold.

Boundary worth stating: naming is exactly where our index is thinnest for this material. Large parts of the index are faces we have no name for — our similarity data alone contains thousands of references to unnamed identities — and coverage is concentrated, with 2,246 of 2,333 representative images coming from a single source. For amateur series, a "no confident match" result is a common and honest outcome.