Si ça t'intéresse, un des mes reviewer préféré sur MAL (Archaeon) a fait une review très représentative de ce qu'est Gintama.
There are lots of anime that feature some sort of humour, however outright comedies are still few and far between (whereas outright parodies are fairly common, but are very much dependent on knowledge of the reference). Part of the reason for this is the method in which comedy is handled in anime, with most shows featuring a lot of parody to shore up the weaknesses in other humourous aspects. Anime, especially outright comedies, have one big weakness though - situation comedy.
That doesn't mean that there aren't any good sit-coms in anime. Nodame Cantabile, Genshiken and Moyashimon are great examples of situation comedy at it's best, especially in terms of anime. Historically though, anime, as a medium, has never really had a series where the main focus was fun and humour in manageable portions, as all too often the tendency is to go overboard.
One series has, however, defied all the conventions, and has become one of the greatest comedy anime of all time. Incorporating elements from some of the best comedy of both East and West, the series has an anarchic streak that, at times, is more reminiscent of Monty Python, The Simpsons and Family Guy.
I am, of course, talking about Gintama.
The concept of a samurai sit-com isn't new to anime and manga, however it wasn't until the serialisation of Sorachi Hideaki's manga in 2003 that anyone actually realised the potential in this type of story.
Set in a quasi-historical Edo, Japan, and possibly the rest of the world, has been conquered by an alien race known as the Amanto. Japan's strongest warriors, the Samurai, were no match for the alien technology, and in an effort to prevent another samurai uprising, the powers that be have banned humans from carrying swords in public.
In this world there lives a former samurai with silver hair, who runs the firm known as Yorozuya from his rented second floor apartment, and takes on odd jobs (yorozuya), for people in order to pay his rent and buy milkshakes and his beloved Weekly Shounen Jump. He is Sakata Gintoki, a man once feared as the "White Demon" during the samurai uprising.
To say that the story is a bit on the haphazard side is probably a gross understatement, however Gintama is nothing if not consistent in it's approach. The underlying story is of Gintoki and his "friends", Shimura Shinpachi (an average human teenager with no real special qualities), and Kagura (an alien who looks human and possesses monstrous strength), as they go through their days doing odd jobs for people, and trying in some small way to make the world a better place.
And that is really about as serious as many of the episodes get. The haphazard approach to the story is a purposeful measure that actually works very well given that Gintama is a comedy series. There are story arcs that occur throughout the course of the anime, and even though they may include some serious or dramatic content, Gintama never once loses it's sense of fun. Indeed, the comedy is the true strength of this series, not simply in it's style and delivery, but also in it's content. Some of the visual gags are extremely good, and whilst the series is top-filled with parodies, it never once over-uses these references, instead turning some of them into running gags that appear throughout the show.
That said, Ginatama has one aspect that is greater than all others in terms of it's plot and comedy content, and that is it's ability to turn the seemingly ordinary into something completely different. This is the main reason why I class Gintama as a sit-com rather than a parody, as this aspect has more in common with shows like Blackadder and Monty Python than anything else. I can't count the number of occasions when the series has caught me off guard with it's slyly anarchic take on seemingly normal events (like being in a public toilet and running out of paper).
Of course, there are downsides too. Although the series is extremely strong in terms of comedy, it sometimes lacks when events take a serious turn. This may be due, in part, to the audience's reactions as viewers may automatically think that something funny is going to happen next, however a part of it also stems from the fact that the comedy is sometimes too "strong". It's ironic really, that Gintama's greatest strength is also it's biggest weakness.
As with any long running shounen series, animation and design are pretty good on the whole. The character designs are extremely well done, and convey a sense of visual individuality that, at times, goes beyond that of other shounen anime. The colours are extremely bold and solid, whilst the backgrounds and set designs highlight the synergy between alien technology and Edo. The animation itself is of an extremely high standard, so much so in fact, that some of the visual gags only really work because of it.
One of the high points of the art and animation is the show's ability to parody other things well. There are numerous occasions when the style, animation, end even the character design, changes to make the humour more immediate. These changes can sometimes occur in the blink of an eye, but can also last for a good portion ofthe episode. The series also plays around with a variety of concepts that most people only really read about, the best example being an occasion where Gintoki and the gang are rendered invisible because the anime is incomplete. I can't honestly think of any other series that not only mentions something like this, but also shows the viewer what it would look like.
With regards to the humour, much of it comes from the characters themselves, but no matter how good the scripting is, delivery is everything when it comes to comedy. In this respect Gintama is extremely well served by it's seiyuu. The cast are able to perform with a panache that is sometimes astonishing, and their portrayals of their respective characters is so good that you'd be forgiven for thinking someone else was acting. Possibly the best example of this is Kugimiya Rie, who plays the part of Kagura. I will freely admit that I'm not a huge fan of hers, mainly because she is typecast into tsundere roles, however her portrayal of Kagura is truly excellent, especially in terms of comedy. Like the rest of the cast she has managed to not only maintain consistent character for a long time, but has actually become more adept at her delivery.
In terms of sound, Gintama is generally consistent with it's choice of music. There are certain tracks that are repeated throughout the series, and that add to the comic atmosphere of a given scene, however some of the more serious moments can feel a little off-kilter because the score changes can be a little bit sudden. As with any long running series, the OP and ED have changed since the show began airing in 2006, however these tracks are usually pretty good at capturing the essence of the show as a whole, especially with the introductory sequences being choregraphed to highlight the important aspects - humour, fun, some seriousness, and a large slice of anarchy.
In all honesty, there is no real reason for me to find the characters outstanding, yet they are, and this is possibly Gintama's greatest triumph. Each of the characters, from Gintoki, Shinpachi and Kagura, to the members of the Shinsengumi, and all the sundry characters, alien and otherwise, who appear in the show are, without doubt, memorable. When taken as individual characters, each is a flawed creation that really wouldn't work were this any other anime, however the plot and scripting for the series, together with the talent of the seiyuu and the design of each character, turns this idea completely on it's head. Much of the comedy in the series is very much dependent on the characters, and it's because the show is so good at entertaining the audience that any noticeable flaws are generally forgiven or ignored.
Gintama is not simply a funny anime though. Over the seasons the show has gradually become a phenomenon in anime, especailly in light of the show's ability to maintain consistent humour for over 120 episodes. The irreverent and oh-so anarchic humour can, at times, come off as wierd, however this has only served to endear the show to more fans - myself included.
That doesn't mean I'm an absolute addict of the series. I've heard many fans refer to Gintama as their "anime crack", and I can understand their perspective (I may not be hooked, but I am definitely a fan). The series has a lot to offer if you approach it with the right mindset.
The show will most definitely appeal to shounen fans, not simply because it bears all the hallmarks of shounen anime, but also because it isn't afraid to to parody other shounen series (Bleach, Naruto, One Piece, etc - who can forget the infamous DragonBleaPiece movie trailer). Fans of other comedy series, especially Seto no Hanayome and Jungle wa Itsumo Hale Nochi Guu, will also find Gintama's ability to mess with everyday concepts worthwhile.
There are a lot of aspects to this show that have a broad appeal in terms of humour, and it's to the show's, and the cast and crew's, credit, that the series never gets old or stale, or too bogged down in how good it actually is.