Data & Methodology

When the data updates

Data is collected and the site is updated automatically every day at 0:30 Japan time. Dates and times are in Japan time unless stated otherwise.

If a day’s collection fails, that day’s summary is not created and the site keeps showing the previous data (this is why some dates are missing from the archive).

Anime charts: trending, popularity and rating

The charts cover Japanese anime that are currently airing and listed on AniList (https://anilist.co), excluding adult titles. The data is fetched once a day from AniList’s official API, and each of the three charts shows the top 30 titles.

Trending: titles ordered by AniList’s “trending” value, an indicator of how much activity a title is getting on AniList. How it is calculated is decided by AniList.

Popularity: titles ordered by the number of AniList users who have the title on their list.

Rating: titles ordered by the average score given by AniList users. Titles with 20,000 or fewer list entries are left out of the rating chart, because scores from a small number of people are easily skewed.

“Weekly gainers” compares today’s list count with the count seven days earlier. “New this week” are titles that were not in any of the trending, popularity or rating charts before that week began.

How to read ratings on title pages

The stars and numbers on title pages are ratings by AniList users, not by users of this site. They are not TV ratings or sales figures. They reflect the people who use AniList, so they can differ from how popular a title is among Japanese viewers overall.

For older titles, the “overall score” is the average of the scores from several sites in the Anime Offline Database (out of 10), shown out of 100. It is a different number from AniList’s score.

Season lists and the weekly schedule

Lists for the current and next season are built every day from Japanese TV and streaming anime on AniList (up to 150 titles, by popularity). Air dates and channels come from the first broadcast in the official API of Syoboi Calendar (https://cal.syoboi.jp/) when it is available; otherwise the time of the next episode on AniList is used (marked with an asterisk). For titles already airing, the next episode on AniList is preferred because it reflects the current time slot.

Weekdays and times follow the Japanese TV-guide convention: broadcasts between 0:00 and 4:59 are counted as 24:00–28:59 of the previous day and grouped under the previous weekday (e.g. Saturday 25:30 is actually Sunday 1:30).

The weekly schedule lists the next episode of each airing title, day by day, for the next seven days.

Steam concurrent-players chart

Once a day we fetch the top ~100 titles by the number of players playing at the same time from Valve’s official Steam Web API. “Week-over-week” is the difference from the previous week’s rank published by Steam.

The API does not include game names, so names and release dates are filled in from Wikidata (CC0) using the Steam application ID. Games with no Wikidata entry are not shown because they cannot be named; ranks stay as Steam reports them and gaps are not closed. Games released within the last 30 days get a “New” badge (only when the release date is known to the day).

VTuber stream schedule

Once a day we fetch upcoming streams, from the time of collection to about 26 hours ahead, from Holodex’s official API (https://holodex.net/). No agency is excluded. We do not collect or show statistics such as subscribers, views or concurrent viewers, and we do not show “live now” (a once-a-day collection would be out of date quickly).

How the text is written, and the checks before publishing

Headlines and lead sentences are generated mechanically from the numbers. The “Today’s points” notes are written by AI (Claude), but they may only use numbers and titles that appear in the collected data.

A note is published only if it passes both (1) automatic checks (are the numbers in the data, are the titles exact, are there no banned expressions such as scandals, spoilers, unconfirmed information or invented personal experiences) and (2) a fact check by a separate AI. If it fails, it is rewritten; if it still fails, plain template text with the numbers is used instead.

Japanese synopses on current-season title pages (short AI summaries based on AniList’s English descriptions) go through the same kind of checks, and any that fail are not published.

The “This week’s notes” on weekly recap pages are written by AI from the numbers in the daily digests of a finished week only. The numbers (days at #1, popularity gains, rank changes and so on) are calculated by a program into a list of facts, and the AI picks facts and writes one sentence for each (no reasons, predictions or opinions). Only notes that pass the same automatic checks and a fact check by a separate AI are published; a week whose notes fail is left without notes.

Limits of these numbers

The numbers cover only the users and the scope of AniList, Steam and Holodex. They are not sales, TV ratings or view counts. Many AniList users are outside Japan, so rankings can differ from popularity among Japanese viewers.

Outages, specification changes or rate limits at a data provider can leave numbers out of date or missing.

Corrections and contact

If you notice a mistake in a number or a sentence, please write to contact@oshicharts.com. We will review it and fix it promptly.

Data sources and rights are covered on the About page.