I'm gonna start making a manga (comic book series drawn with anime style), and I'm wondering, what setting should it have?

Present Setting - Most likely with gun-slingers and such. mayb some mafia (probably not, though).

Past Setting - Not normal past, GOOD past. With magic, and swords, and monsters.

Time-Crossing Setting - Mayb a virtual reality thing about the past, that is used in the future. Complicated, but really cool ^^