Recently, discussions about the longest-running anime have attracted many participants. Contrary to the beliefs of many, even though the manga One Piece has surpassed 1,000 volumes, it is not the longest-running anime.
In fact, the longest-running anime globally and specifically in Japan is Sazae-san. In 2013, the Guinness World Records recognized Sazae-san as the “longest-running animated television series” in the world.

Debuting in 1969, Sazae-san is adapted from a comic strip of the same name by the famous Japanese cartoonist Machiko Hasegawa. The anime follows Sazae, a housewife living in Tokyo, and chronicles various everyday occurrences and the challenges faced in family life.
While Sazae-san may not be as internationally renowned as Pokémon or Doraemon, it has become a cultural phenomenon in Japan, airing continuously for over 54 years. With weekly episodes divided into three segments, Sazae-san provides insights into the lives of a Tokyo family, addressing societal challenges over several decades.
The success of Sazae-san lies in its relatable characters, allowing viewers to see themselves reflected on-screen and share in the joyful escapades of the characters.
Machiko Hasegawa, the creative mind behind Sazae-san, not only created a cultural icon but also inspired many women to pursue careers in the manga industry.

Alongside Sazae-san, here are other anime series known for their lengthy episode counts:
1. Sazae-san: Over 7,500 episodes since 1969.
2. Lan Mao: Over 3,000 episodes from 1999 to 2001.
3. Nintama Rantaro: Over 2,350 episodes and still ongoing.
4. Ojarumaru: Currently has over 1,947 episodes.
5. Oyako Club: 1,818 episodes from 1994 to 2013.
6. Doraemon: 1,787 episodes from 1979 to 2005.
7. Kirin Monoshiri Yakata: 1,565 episodes from 1975 to 1979.
8. Chibi Maruko-Chan: Continually developing since 1990.
9. Sorike! Anpanman: 1,491 episodes as of 2013.
10. Manga Nippon Mukashibanashi: 1,471 episodes from 1976 to 1994.
Other well-known anime like Pokémon, Detective Conan, One Piece, and Naruto also have impressive episode counts.
According to Animerant