The Nintendo DS game version of Shin Megami Tensei: Devil Survivor has a decent story line. Three teens are given specially modified COMPS (Nintendo DS like devices) that can summon demons and control them. They'll come in handy since something big is happening in Tokyo. Demons keep appearing and killing people, and in 7 days the city, and maybe the world, are going to be destroyed. It is up to the main character (whom you name and control) to figure out what is going on before it's too late.
The storyline is really interesting and had me hooked from the beginning. The location is great, Tokyo, and has the same hip feel as The World Ends With You. I just wish the gameplay lived up to it.