Itoi is the big name in this trade, as I wrote about him last year and called him an OBP machine. A converted pitcher, as a corner outfielder, he doesn't hit for much power, unprototypical for that position. It has long been rumored that he Itoi wanted to come to the states, and in fact, an article earlier Tuesday stated that he wanted to be posted after the 2013 season. So the Fighters, clearly the best run organization in the NPB, may be hedging their bets a little here, trying to get some value before he leaves. As far as future MLB talent, Itoi is the only guy in the trade that has any real future value in my opinion. There are some questions about where he will fit defensively, and whether or not the approach will translate, but he is clearly the best player in this trade.
Tomoya Yagi is a 29 year old left-handed starter, who made 13 starts for the Fighters in 2012. Always seemingly a part time pitcher (though he has only made starts in his career, never pitching out of the bullpen in Ichi-gun), Yagi had a 4.52 kwERA in 2012, or a 105 kwERA. A soft tossing left, he averages between 83 to 84 MPH on his fastball, throwing a lot of soft sinkers and sliders.
I actually wrote a little about Hiroshi Kisanuki last year. There was no reason to be a fan of him statistically before the 2012 season, but the 32 year old right-hander made 21 starts (24 appearances) and had a very good ERA. However, his DIPs were less impressive, with a 103 kwERA - and 101 FIP - (as the Buffaloes park has played basically neutral over the past two seasons). He has a mediocre fastball, that has averaged just over 86 MPH over the last 3 seasons. He mixes in a somewhat slow curve (a 72 MPH curve is not that slow in the NPB), a 80 MPH slider, a forkball, and occasional moving fastball. According to heat maps (by NPB Tracker), he does a good job of keeping the ball low.
Keiji Obiki is a 28 year old right-handed hitting shortstop with some good but not great defensive data. He had been Orix' starting shortstop, and easily out hit Nippon's starting shortstop, 37 year old Makoto Kaneko. Over the past two seasons, Obiki's OPS has been about .070 points better. While the Fighters park is pitcher friendly (95 Park Factor over the last two seasons), it doesn't account for that big of a difference and the defensive data seemed to favor Obiki as well.
Shogo Akada, at age 32, is actually a year older than Itoi. Another outfielder, Akada has really struggled in recent years, especially in 2012 where he played in just 26 games and had an OPS of .434. Assuming he isn't an elite defender, and there isn't anything in the data to suggest this, he is really a non factor and just a reserve outfielder that may play in the Ni-Gun and provide some organizational depth.
For the Fighters, this really just feels like a trade in which they felt they had to get rid of Itoi. They upgraded at shortstop, which was a desperate need, especially with Kensuke Tanaka leaving for the San Francisco Giants, but they clearly downgrade their outfield and I don't think there is much reason to believe that Kisanuki will be near as good in 2013 as he was in 2012 (at least by ERA standards). I was really surprised they didn't add to their farm system, as that would be more productive than getting older players in Akada and Kisanuri that won't help them all that much. This especially seems apparent when there top two hitting prospects are catchers, and their top rated outfield prospect is Yuya Taniguchi, a 20 year old outfielder who has good defensive skills but was an average hitter in the Ni-Gun in 2012. Since Shoga isn't going to be able to replace Itoi, Taniguchi might have to be that man as early as 2013, and it doesn't appear the bat is ready.
Nippon slightly upgrades their rotation for 2013, but since Yagi is younger, Orix probably takes the advantage long term. Obviously they acquire perhaps the best hitter in the NPB to help bolster the offense of a team that lost 20 more games than it won in 2012. The main question is what their rotation will look like. With Alfredo Figaro in limbo, and Kei Igawa struggling in 2012, the rotation has a lot of questions outside of Yuki Nishi