Slime Season 4 and Bookworm Land in Japan's Top 10 Anime Ratings for Spring Week 1

Japan's first weekly household anime ratings of the spring 2026 season show long-running institutions holding the top three slots, with three major spring premieres placing inside the top seven. Video Research's survey for the week of March 30 through April 5 captures the opening week of the season and sets the baseline the newer series will be measured against through June.

The Top 10

Sazae-san: 7.5 percent. Fuji TV's Sunday evening family staple continues its decades-long reign at the top of the rankings. The combination of multi-generational appeal and the 6:30 p.m. time slot keeps the programme insulated from the weekly premiere competition that shuffles the lower rankings.

Detective Conan: 6.0 percent. The long-running Nippon TV mystery series posted its usual Saturday evening number, reflecting the viewership that routinely carries over from the franchise's theatrical releases back into the weekly episodes. The most recent theatrical film's strong run is adding weight to the television number.

Chibi Maruko-chan: 5.7 percent. Fuji TV's other long-running Sunday family programme holds the third position comfortably. Its audience is the closest direct overlap with Sazae-san's and moves in similar seasonal patterns.

That Time I Got Reincarnated as a Slime (Season 4 premiere): 3.1 percent. The opening episode of the fourth season scored the highest debut of the week, placing the isekai franchise comfortably ahead of the other new premieres. The five-cour commitment announced earlier in the spring gives the show a sustained presence through the rest of the year.

Doraemon: 2.8 percent. TV Asahi's family property continues its weekly run, with the recent theatrical release pulling additional audience back to the television slot.

One Piece (post-hiatus resumption): 2.5 percent. The long-running Toei Animation property returned from its brief production hiatus with the opening episodes of the Elbaf arc. The rating reflects the series' stable weekly audience rather than the fresh-arc bounce the show typically gets a few weeks into a new storyline.

Ascendance of a Bookworm Part 3 (premiere): 2.4 percent. WIT Studio's return to the franchise launched with the opening episode of the third part, drawing the second-highest premiere number among new spring shows. The production team's opening-sequence redo, announced after episode one, has drawn significant coverage but did not dent the debut rating.

Crayon Shin-chan: 2.3 percent. TV Asahi's other family comedy rounds out the top eight in its usual slot. Its rating moves within a narrow band season-to-season and holds independently of premiere dynamics.

Star Detective Precure: 1.8 percent. The current Precure series, which premiered in February, is stabilising into its standard weekly audience after the early-run peak.

(tied). Animated O-saru no George (Curious George): 1.6 percent and Oshiri Tantei Season 10 premiere: 1.6 percent. The tie at tenth gives the Curious George adaptation and the tenth-season opener of the Oshiri Tantei franchise equal billing in the opening-week list.

What the Numbers Say

Household ratings in Japan measure broadcast viewership in the Kanto region and exclude recorded playback viewed later in the week. That framing matters for the rankings here: the top slots reflect live family viewing patterns more than the late-night blocks where most of spring 2026's genre premieres air. Shows like Drops of God, Witch Hat Atelier, Yowayowa Sensei, and Fist of the North Star, which debuted across the week in late-night slots, do not appear in the list because their recorded and streaming viewership is not captured.

The Slime Season 4 and Bookworm Part 3 entries are the most meaningful late-night premieres that still punched into the weekly household list, and their positions point to the same programming pattern as prior successful spring seasons established franchises crossing over from niche fandom into family viewing hours.

Indian Context

For viewers tracking these shows from India, the top 10 household hits and the late-night genre premieres diverge almost completely from each other. Crunchyroll India, Netflix India, and Prime Video India carry most of the spring 2026 late-night shows that fall outside the Japanese household list, and the streaming numbers from those platforms are what Indian audiences encounter daily. The Japanese household list is useful as an adjacent signal rather than a direct guide for Indian viewing choices.

The Next Measurement

Video Research's next weekly snapshot will cover the April 6-12 window, which is the first full week that includes the stragglers Fist of the North Star, Mission: Yozakura Family Season 2, Odekake Kozame Season 2, and Ichijyoma Mankitsu Gurashi. Their household numbers will decide whether any of the late-night premieres can push past the top-ten threshold as the season continues.