📺 Forget fan polls for a second. What if you could see what 620,000 Japanese TVs actually watched — not the show people hyped, but the show they sat through, episode after episode? That ranking now exists, and the spring 2026 winner is That Time I Got Reincarnated as a Slime Season 4. Here's why that result looks nothing like the charts overseas fans are used to.

A ranking built from real TVs, not votes

On May 22, Japanese TV maker TVS REGZA published its mid-season viewing ranking for spring 2026 anime and dramas. The headline result: in the "series" category — shows that have aired before and are continuing — That Time I Got Reincarnated as a Slime Season 4 (known in Japan as TenSura) finished first, and not by a little. The press release describes its lead over the second-place title as more than double.

The rest of that top five tells you something about Japanese TV viewers right now. Every single one is an isekai — a "transported to another world" fantasy. Slime is followed by Farming Life in Another World, Ascendance of a Bookworm, Re:ZERO Season 4, and another reincarnation-themed sequel. For the audience watching anime on an actual television set, the comfort of a familiar fantasy world is winning.

TVS REGZA spring 2026 anime and drama viewing ranking key visual

Source: TVS REGZA Inc. / PR TIMES

So what exactly is this "620,000 REGZA TVs" data?

This is the part worth slowing down for, because it changes how you should read the ranking.

REGZA is one of Japan's major television brands. Its sets can log what they display — down to one-second precision — and owners who opt in let that data be collected and analyzed. Nationwide, that adds up to about 4.62 million REGZA TVs as of October 2025. For this particular ranking, REGZA used a slice of that fleet: roughly 620,000 sets located in Tokyo, Kanagawa, and Saitama — the three prefectures that make up the core of the greater Tokyo area.

The crucial difference from a standard TV rating is what counts as having watched something. Normal ratings tally any set that was tuned in, even for a single minute. REGZA's ranking is far stricter. A device only counts if it watched at least one-third of an episode. And to be counted for the season ranking, that device also has to have watched 70% or more of the episodes aired so far. Recorded playback gets folded in too, as long as it happened within seven days.

Strip away the jargon and it comes to this: the ranking does not measure who is curious about a show, or who caught a buzzy clip. It measures who actually committed to a season and kept showing up. It is a "did you stick with it" chart, not a "did you hear about it" chart. That is exactly why REGZA frames it as the anime that is genuinely being watched.

One honest caveat. This is broadcast-TV behavior, sampled in the Tokyo region, on physical TV sets. It naturally leans toward people who still watch anime the traditional way — live or via a DVR — which tends to skew a little older and more domestic than the streaming crowd. It is a real, valuable signal. It is just not the whole country, or the whole audience.

Overseas, a completely different lineup is winning

Now hold that Japanese result next to what fans outside Japan are voting for.

Anime Corner runs a weekly poll that draws thousands of votes from anime fans worldwide. Across the spring 2026 season, the number-one spot has rotated between Re:ZERO Season 4, Witch Hat Atelier, and Wistoria: Wand and Sword Season 2. Slime Season 4 has not been part of that conversation at all.

The gap is not subtle. When the entertainment site CBR previewed the season, it noted that the big returning series — One Piece and Slime — were not expected to be as jaw-dropping as the previous season's heavy hitters. Anime News Network's premiere review was blunter still, calling Slime's third season "offensively boring" before grudgingly admitting the new season opens better than that.

The most striking detail is buried in REGZA's own press release. It points out that Witch Hat Atelier — a show fighting for the number-one or number-two position overseas — lands only around ninth in Japan, and even that is its single best demographic placement. The overseas darling is a niche pick on Japanese TVs. The Japanese number one barely registers on overseas polls. Same season, same shows, two almost unrelated charts.

Why the two rankings disagree so much

The mismatch is not a mystery once you line up what each chart is actually measuring.

A weekly fan poll captures the most exciting episode of the week and the loudest hype. It rewards shows with dramatic spikes and gorgeous, fresh visuals — which is why a brand-new title like Witch Hat Atelier can shoot to the top on the strength of one stunning episode. REGZA's data rewards the opposite: quiet, complete, week-after-week loyalty across an entire season.

Platform plays a role too. Overseas fans mostly watch on Crunchyroll, one episode at a time, and vote on whichever release hit hardest. The REGZA sample is people watching on a TV set in the Tokyo area — a more habitual, more routine kind of viewing, where a long-running isekai sequel functions like comfort food. You already know the world, the characters, the rhythm. You just keep watching.

Neither chart is wrong. A hype poll and a completion-rate dataset were never going to crown the same champion. They are answering two different questions: "what excited people this week" versus "what did people actually finish."

What the data quietly reveals about Japanese viewers

Because REGZA breaks its numbers down by age and gender, the ranking doubles as a little portrait of who watches what.

Women aged 20 to 34 stand out for almost completely avoiding isekai — their chart is dominated by other genres entirely. Daemons of the Shadow Realm, the new fantasy from Fullmetal Alchemist creator Hiromu Arakawa, performed well across every single age-and-gender group, the kind of broad reach that mirrors its manga's reputation.

There is also a neat scheduling story. In the "new shows" category, the surprise number one was an original sci-fi series called Snowball Earth. REGZA's own read is that it benefited heavily from its time slot: it aired right after Slime Season 4 on Nippon TV, inheriting a huge, already-seated audience. With four more cours of Slime still to come, REGZA suggests that post-Slime slot is about to become very valuable real estate.

Where to watch Slime Season 4 if you want to judge for yourself

That Time I Got Reincarnated as a Slime Season 4 is streaming on Crunchyroll across North America, Latin America, Europe, Africa, Oceania, the Middle East, the CIS region, and Southeast Asia, with new episodes on Fridays and both subtitles and an English dub. The season is a big one — five cours and roughly 60 episodes in total, with the first two cours running back-to-back. The franchise itself has topped 56 million copies in circulation worldwide as of late 2025, so the Japanese TV audience that keeps tuning in has plenty of company.

Whether Slime deserves the crown is, of course, a matter of taste. What the REGZA data really shows is that "most popular anime" depends entirely on how you measure popularity.

So here's the question worth turning over: when you start a new anime season, are you a finisher who sees every show through to the end — or a sampler who drops half of them by episode three? If a ranking only counted shows you completed, what would your personal spring 2026 chart look like?

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