One piece is about pirates and a dude who wants be the pirate king and find the one piece treasure, he accumulates his crew and sets out on an adventure which will have your arse glued onto the chair for a while.
Bleach is about a highschool, hilly billy, son of a betch who gains soul repear powers and begins to defend himself from hollows (evil spirits) and endures a powerful road which lies ahead, meeting new freinds and insane characters, bleach has a good story in the beginning, you might like it, don't take my word for it, tho.