Haikyuu!!
Both the anime and manga versions of Haikyuu!! are among the genre's best-selling titles. This feat was accomplished despite the manga's last edition and chapter having been published more than a year ago. Specifically, the series sold an amazing 4.345 million copies in Japan in 2021, making it one of the year's ten leading best-selling manga series. This achievement might be ascribed in part to the anime's new season's popularity.
While the book managed to sell well after it concluded, at roughly 500,000 volumes per month, it was beginning to slow down at about the 200,000 level. It rebounded in December 2020, coinciding with the anime's new season's premiere, generating over 869,000 copies for that month alone.
This streak has remained strong since then, resulting in a profitable time period for Haikyuu!! Given that the anime has not yet concluded, it seems unlikely that the franchise's popularity would wane in the near future.
Year of Release: 2012
Author: Furudate Haruichi
2021 Sales: ~4.3M copies