Once, I met a beautiful girl who told me, 'This show was my youth!'
I love this show too, and as a kid I'd hide and watch the anime every single week without fail, sneaking it past my parents... but when she'd say things like 'It's so much fun, right? Gintama!' or 'I watched it too! It's hilarious, right? Gintama!'—it's definitely funny, no doubt about it, but being told a girl's youth was Gintama leaves me feeling kind of conflicted, not quite sure how to react.
It's a sci-fi, human-drama, sort-of-period-piece comedy anime absolutely loaded with raunchy humor (a genre the author himself describes that way), a legendary work that aired nearly all of its episodes over a span of 15 years (though there are plenty of episodes that can't be re-aired).

Here's the synopsis.
The end of the Edo period. With the rise of the 'Amanto' who came from space and the sword ban, samurai were on a steady path to decline. Even so, Gintoki Sakata of the Yorozuya, who firmly holds onto his samurai spirit, meets Shinpachi and Kagura by chance. The two begin working at the Yorozuya, and incidents and uproars keep breaking out...

There is a synopsis, sure, but at its core it's a series of self-contained stories that wrap up in one or several episodes, basically a show you can jump into from anywhere.
When a beautiful voice actress appears in Gintama, it's the kind of show where comments get scribbled in the corners of the internet like, 'So that voice actress fell prey to Gintama too,' or 'Guess she got dirtied up by Gintama.'

It's also famous for its 'we're ending, we're ending' scam, repeatedly making it look like it's wrapping up only to keep going. There are even two theatrical anime films, 'The Final Chapter: Be Forever Yorozuya' and 'THE FINAL.' For the record, 'Be Forever Yorozuya' was made to bring the anime to a sort of milestone closure, while 'THE FINAL' depicts the original manga's final chapter.

The franchise spun a long, long string of episodes across four series: 'Gintama' (aired 2006–2010) as Season 1, 'Gintama'' (aired 2011–2012) as Season 2, 'Gintama' Enchosen' (aired 2012–2013) as the Season 2 extension, 'Gintama°' (aired 2015–2016) as Season 3, and 'Gintama.' (aired 2017–2018) as Season 4. But every one of them was full of risky material (mainly with the BPO) and constantly making enemies, so for those of us watching, it was genuinely a show that could've ended at any moment. When it moved from an evening slot to a late-night slot, I thought it was over—the fact that it managed to end on its own terms is a miracle.


Also, since it faithfully recreates the manga, there were apparently many times when the anime caught up to the source material, like with Dra○on Ball Z or One ○iece. But there aren't that many anime-original episodes—it respects the original work. As a result, there were times when they'd stretch things out using a single still image while the voice actors made meta comments and the like. Fans of Gintama will surely remember this when they hear this track.
The title is 'I'm Getting Too Old to Stay in Jump, Aren't I.'

https://www.youtube.com/watch?v=EV0BtHh0XhI&list=PLKwYE53e62mXG4COKRUsbDtZDOzFzOYyD&index=4



This anime is also rich with gags, slipping snide remarks or gripes into the sponsor credit orchids and generally serving as an outlet for the staff's stress.
Well, you'll get the idea once you hear this track.
The title is 'You Bastards!! Do You Even Have a Gintama on You?!'

https://www.youtube.com/watch?v=ZyAaMdcb6H0&list=PLKwYE53e62mXG4COKRUsbDtZDOzFzOYyD&index=1


Lastly, let's wrap up by checking out the trailer for the only original theatrical film, 'Gintama: The Final Chapter - Be Forever Yorozuya.'

https://www.youtube.com/watch?v=UhJM5rVqaF8
Gintama anime visual

Quoted from the official site https://www.tv-tokyo.co.jp/anime/gintama/index.html