so smoking means you are alive nee~? O.o

That was what I got out of that dj too...

You can smoke because you are alive. Sometimes when u go thru sad times, u can't really tell if your alive. Pain, and in this case, smoking told them that they are indeed alive. This is the way I see it.

They smoke to honor Sakura, to keep her alive symbolically. It': also a coping mechanism for her death. The two of them probably feel guilty for outliving her like most people do when someone dies into same situation/accident as them.