Several months ago I reviewed the first season box set of Yu Yu Hakusho, which covered episodes 1 through 28. This second season release from FUNimation covers episodes 29 through 56.
The first season introduced us to the main characters, and included a tournament segment to decide who would be the heir to Genkai's special technique. It left off on the introduction to the Dark Tournament, a tournament for teams of demons (or the rare highly skilled humans) to compete against each other for a grand prize. This second season follows this tournament, but does not conclude it; you'll need to buy season 3 for that. It covers most of it, and ends at the beginning of Yusuke's team's final round against Team Toguro.
Due to the season's focus on this tournament saga, there's not a whole lot of (over arching) story or character development. Each of our heroes grow in power, but there's not a whole lot of individual character progression. The exception here is Genkai, who has her big moment within the season; we learn about her past and why she chose to disguise herself to attend the tournament. We also say farewell to the aging master, as her past comes back to haunt her.
Yusuke's growth is mostly dependent on Genkai. In the last season, he went through intense training to get ready for the tournament, which gave him the ability to use his spirit gun more than once per day (he also developed some new ways to use it). This season he goes through yet another training period with Genkai to learn her special technique, and finally hatches his spirit egg (from the beginning of season 1). Kuwabara gets some help from Kurama and learns new ways to use his spirit sword. Kurama's biggest secret is revealed, as is his true power (and his incredibly sexy true form). Hiei struggles to control his Jagan Eye and the overwhelmingly powerful hell fire he can summon. The girls take a back seat, almost literally, as simple spectators of the tournament. Keiko, Kuwabara's sister and Botan all travel to the arena to watch Team Urameshi, providing some commentary and proving that it's not just the contestants in the tournament whose lives are in danger. Koenma also attends, as the "owner" of the team.
Things are a bit more serious this time around (though the fantastic cheese and comedy still abounds). The gang truly struggles with mastering their individual power, and fighting in a tournament that is continually stacked against them. It takes a lot of hard work and some self sacrificing to get to the final round of the tournament. Along the way we're introduced to all sorts of combatants, and several of them make return appearances later in the tournament, and will return again during other sagas in the other seasons.
DVD extras once again include season appropriate character profiles and clean credits. DVD sleeves are reversible (with tinted sketches instead of color pictures on the reverse side) for the box's 2 cases (which contain 4 DVDs).