Bleach is a long-running story originally written in Japanese. It is Kubo's second series, and has become a huge success in Japan and across the world. Recently, Bleach won the prestigious Shogakukan Manga Award in Japan in the boy's category.
The story and the art are both products of Kubo himself, and both are superb. The main character, Kurosaki Ichigo (or, for us Americans, Ichigo Kurosaki), starts out as just a normal, 15-year-old boy - going to school, surviving the everyday troubles in his home (shared by his father, who runs a clinic, and his two younger sisters), and generally being a stubborn, determined, impatient, impulsive teenager.
Oh, and helping the ghosts he sees cross over into the next life. You know, just general teenage stuff... right.
One night, he meets a woman who will change his destiny forever: a Soul Reaper ("shinigami" in Japanese) named Kuchiki Rukia. Rukia has come from the Soul Society - the spirit realm - to kill an evil spirit that threatens Ichigo's family. However, when Rukia realizes that Ichigo can see her, even though she is a spirit, she is amazed. Ichigo is not just a normal human: he can see spirits, he has immense spiritual energy, and, when Rukia places a binding spell on him to get him out of her way, Ichigo breaks it under his own power - something no human should be able to do.
This immense spiritual pressure of Ichigo's turns out to be the reason why the evil spirit (the Hollow) has come to attack Ichigo's family... it wants to devour Ichigo's soul. Both of Ichigo's sisters are injured in the battle, and Rukia, in a desperate attempt to save Ichigo's life, becomes too injured to continue the fight. There is only one remaining option: Ichigo must take Rukia's powers and become a Soul Reaper if he wants to save his family's life. In order to accomplish this, Rukia drives the point of her spiritual sword (called a zanpakuto) through Ichigo's heart...
...and Ichigo is transformed into a Substitute Soul Reaper. Now his spirit has the same powers as other Soul Reapers, and he wields his own zanpakuto. He defeats the Hollow and saves his family, and everything seems to be just fine... until Rukia shows up at his school the next day, pretending to be a transfer student. She has lost all of her Soul Reaper powers to Ichigo and is trapped in the human world as a mortal until her powers regenerate and she can return to the Soul Society. And until she can continue her work on her own, Ichigo must help her fight off the Hollows that threaten Karakura Town where he lives.
The more he works with Rukia, the more Ichigo grows in strength and power... and the more Rukia realizes that Ichigo is headed far beyond anything she has ever seen.
The plot is well-developed and the character cast is large and varied, making for plenty of interactions and side stories that reveal something important about one of the main characters. For a much more detailed look at the characters (or in fact anything about Bleach that catches your eye) I recommend checking out the Bleach wikia. Amazon.com has both the Manga and the DVD collection available to order. The DVD series stays very true to the original Manga storyline, although there are some episodes that were specifically written for the TV version (in order to give Kubo more time to write). The anime even uses Kubo's own art and most of the same dialogue. If you want the "true" Bleach experience, I suggest watching the anime in Japanese (with English subtitles of course, so you know what's happening). The DVD sets are set up to play both the Japanese and English versions with the option of English subtitles. Hulu.com has all of the Japanese episodes (with English subtitles); they are currently working to secure the rights to stream the English version as well.
Trivia Question: Name at least four characters who can use Bankai, and give the name of the Bankai.