Fan service is a hot-button topic in the anime fandom, frequently sparking heated debates and vicious arguments. While some people adore it and can't get enough of it, even a hint is enough to put others off a show for good. For older anime series, fan service was much more common, with it cropping up in the most unexpected shows. Fan service has a long and fascinating history.
Source：https://www.cbr.com/fan-service-classic-anime/
