I'm still asking myself why I chose this as my first-ever review on this site, as it is rather tricky to review a series where many people would completely disagree with my opinion. However, I've chosen to ignore that fact and present this review to the best of my ability.
Tsubasa Chronicle is probably one of the most debated CLAMP works to date, be it the manga, anime or OVAs. Former CLAMP fans and readers/watchers new to the CLAMP universe (or CLAMPverse) are divided in their opinions - some praise it for the art and complexity of the plot, while others criticise it for the same reasons. However, this review deals only with the Tokyo Revelations OVA.
First off, if you haven't read the manga up until this point, stay away. Many people may look upon this OVA as a continuation of the anime series (which is what I thought it to be as well before watching) but in reality, it continues from where the plot of the anime deviated from the plot of the manga. I also warn you, this is not a happy arc, so if you are used to the overall optimistic side of the series and cannot see it from this perspective, do not watch this OVA.
As far as the story goes, it is a direct adaptation of the manga arc in question. The world of Tokyo and the events concernng it were interesting, and a particularly large revelation was made here (which I won't reveal, for those who haven't seen it yet). Overall, the storyline of this arc is good and well laid out in the anime as well.
The animation, as expected of Production I.G., is fabulous. I.G. is known for its high-quality animation and as this is an OVA, the budget spent on it was larger than on the anime. And it shows. The action is more pronounced, the backgrounds well-illustrated and the characters show much more emotion, as compared to the dull emotionless eyes in the anime before it. A perfect score in this department.
Yuki Kajiura's music brings the right amount of tension to dramatic moments, and slows it down perfectly during moments of sadness. The music of this series lives up to her reputation, so there is nothing more that needs to be said. The opening theme is Synchronicity, sung by Yui Makino (Sakura's voice actor). The ending theme, Saigo no Kajitsu, is sung by Maaya Sakamoto, who has featured prominently even in past CLAMP works. Both suit the series well.
The really tricky part of this review is the characters. On one hand, if you consider the personalities of Syaoran and Sakura in Cardcaptor Sakura, they are almost completely different in Tsubasa (regular readers/watchers will know this). This is one reason as to why they have been criticised repeatedly. On the other hand, this change was required for the Shonen demographic and it adapts quite well if you are able to consider them as two almost-separate sets of characters. Or according to the CLAMP principle, "people who have been raised under different conditions but retain the same souls."
In my experience, I happened to find Tsubasa before Cardcaptor Sakura, and as a result, the 'change in personality' did not affect me significantly. The main characters are likeable to me in both series'. As for original characters, Kurogane and Fai may be seen as 'the grumpy one who likes fighting' and 'the ever-optimistic one who always smiles', but their characters run deeper than that. Both have troubled pasts, each one choosing to keep his concealed in his own way.CLAMP does a good job of gradually revealing said pasts, although that doesn't happen in this OVA. However, there is a fairly good amount of character development all the same.
The supporting cast comprises of characters recycled from previous' CLAMP series', the majority being from X/1999 as it appears to be set in the same (or similar) world. I'm not familiar with this series so I did not pay any special attention to them, however, fans will probably appreciate them a little more.
Overall, this OVA adapts the Tokyo arc brilliantly and is almost-completely faithful to the manga that provides us Tsubasa fans with a much-needed improvement from the anime. If you are a fan of CLAMP and/or Tsubasa in particular, I highly recommend it. If you have not seen the preceding anime series, it doesn't matter as long as you are familiar with the manga. In fact, you're better off not watching the anime at all.