Ah I didn't know that because where I live cigarettes are very unpopular and people don't like them because they smell bad but drugs on the other hand are more popular.
Don't think to far off, its an anime, they wouldn't even use any reference to drugs or whatsoever, the most they would is just smoking cigarettes, that's all. Drugs are like a taboo is Japan.
Yeah with the third episode wth the cigarette kid I thought it would have been drugs since you can really smell it when a person has just been doing some dope.