The OVA is divided into two parts. The one you think it's serious but it's actually troll and the one that is 'ahahaha lol we trolled you'.
First part is amazing. Second part is typical Gintama.
The art in the first part is sublime. Second part is typical Gintama.
The sound in the first part is great (the 5th opening song, Donten). Second part is typical Gintama.
You will enjoy it for sure. We Gintama fans are used to being trolled but we still enjoy this troll things. Gintoki's past is something we all want to know and even though this is
fake, it's still great.
The overall is 10 because of the epicness, the war, the troll, the blood, the Zura, the humor, the troll again, the AHAHAHAHA guy, the troll once more, the Takasugi missing his eye, the troll, the mini Gin-san, the troll, the troll, the troll.
Sunrise recognised the demand for a Gintama movie and so took the concept of a teaser, expanded it a little and made Shiroyasha Koutan for the 2008 Jump Anime Tour event. With only a little information and the runtime to go on, many fans assumed the special would be ten full minutes of action - perhaps a full sequence - set during the Joui war, possibly covering sections of main character Gintoki's past. The end result was completely unexpected, but so in Gintama's nature and an absolute treat for fans.
In essence, Shiroyasha Koutan is simply a build up; a supporting act before the main event.
The first four minutes are beautifully re-animated backstory sequences from the main series, spliced with additional footage here and there, that have been pieced together to create a trailer for a fictional Gintama movie. Once the trailer is over, we find ourselves in the movie threatre with the main trio, who begin to eliminate the fourth wall in true Gintama fashion by commenting on their own trailer. Before long the supporting cast show up and havoc ensues, then - time's up! It's over. As the characters bid farewell, they reveal the true purpose of the special; to build up the momentum for the One Piece special that follows!
Shiroyasha Koutan is a completely unpredictable, absolutely frantic ten minutes, as funny and entertaining as Gintama ever was; positively up to standard. The animation is crisp and feature-worthy and all of the main characters and every member of the prime supporting cast are utulised; not one character is underplayed. It's pure entertainment in true Gintama form; if you're new to the series, it'll most likely go over your head, but if you're already a fan, it'll go straight to your heart.
To sum it up simply, the first 3-4 minutes is presented in a serious and somewhat epic manner, revealing a bit of character background and story, along with great quality fighting scenes and of course heartmoving dialogue.
The next part is basically the usual gintama humor and gags that is still in high standards, including the appearance of many adored characters of the Anime. A fitting choice of music played during the start of the 'movie trailer' and as expected of Gintama, it sent us off laughing with the One piece and Dondake ending.
Of course, it's not subbed yet so only the first part is
actually somewhat understandable unless you're fluent in japanese. Never-the-less a great OVA to watch.