The first full week of the fall 2026 season is in, and Japan's TV audience picked its late-night favorite fast. In Video Research's Kanto household ratings for September 28 – October 4, The Apothecary Diaries season 3 debuted at 4.8% — fourth overall and the only late-night show in the top five, per Anime News Network's weekly chart.
Quick answer
The most-watched anime on Japanese TV in early October 2026 were the Sunday-evening institutions — Sazae-san (7.9%), Detective Conan (5.6%) and Chibi Maruko-chan (5.3%) — followed by The Apothecary Diaries season 3 (4.8%), Ascendance of a Bookworm (3.4%), Tougen Anki: Nikko Kegon Falls Arc (2.7%) and a Demon Slayer rebroadcast (2.4%). According to SenpaiRanks, The Apothecary Diaries' first two seasons score 7.67 and 7.69, the highest consensus scores of any new-season show on this chart.
The ranked list
Skipping the two family-hour classics (Sazae-san, Chibi Maruko-chan), here is the anime-fan top five by rating.
1. Detective Conan — 5.6%, NTV, Saturday 6:00 p.m.
The evergreen leads the fan chart: the franchise also pulled an 8.6% for its Counterfeit Crime Case special the week before. Our Detective Conan watch order is the on-ramp.
2. The Apothecary Diaries season 3 — 4.8%, NTV, Friday 11:00 p.m.
OLM's third season opened the Friday Anime Night block on October 2 and beat every family-hour cartoon except the big three. Crunchyroll simulcasts it, and the English dub starts October 16.
3. Ascendance of a Bookworm — 3.4%, NTV, Saturday 5:30 p.m.
WIT Studio's take on the Adopted Daughter of an Archduke arc holds a 7.12 on SenpaiRanks. If you're behind, start with the Bookworm watch order and the Part 4 production update.
4. Tougen Anki: Nikko Kegon Falls Arc — 2.7%, NTV, Friday 11:30 p.m.
Studio Hibari's sequel rides the Apothecary lead-in and keeps a little over half its audience. The new arc's board is open — season 1 sits at 6.61.
5. Demon Slayer (rebroadcast) — 2.4%, Fuji TV, Sunday 9:30 a.m.
A Sunday-morning rerun still out-rated most new premieres. On SenpaiRanks it holds an 8.36 — the strongest score on this list.
How to read it
Household ratings measure who watches live broadcast in Kanto. They miss streaming, overseas viewers and late-night recordings, which is why a show like That Time I Got Reincarnated as a Slime season 4 can post a modest 3.1% (mid-September) and still be a global hit — Slime's next part is dated for July 2027. TV ratings tell you what Japan's mainstream is watching; the SenpaiRanks board tells you what's actually good. Where the two agree — The Apothecary Diaries this week — you have a safe pick.
For the internet-side view, compare this with the most popular anime of October 2026 and last cycle's August ratings vs. ranking report. The full season board is in our best fall 2026 anime ranking and what to watch in fall 2026.
Frequently asked questions
Q: What was the most-watched anime in Japan in early October 2026?
A: Sazae-san led with 7.9%, followed by Detective Conan at 5.6% and Chibi Maruko-chan at 5.3%.
Q: What rating did The Apothecary Diaries season 3 premiere get?
A: 4.8% in the Kanto region, fourth overall for September 28 – October 4, 2026.
Q: Which new fall 2026 anime is most popular in Japan?
A: The Apothecary Diaries season 3, the highest-rated new-season show on the weekly chart.
Q: Do Japanese TV ratings include streaming?
A: No. Video Research household ratings cover live broadcast in the Kanto region only.
Q: Where can I watch The Apothecary Diaries season 3?
A: Crunchyroll streams it subtitled as it airs, with an English dub from October 16.