By now I've accepted that romance yaoi uses terms like "sadist" all the time without the proper meaning being represented in the story... annoying as it is. Also when there actually is BDSM there are never safewords and the BDSM community isn't represented well.
honestly I just think people are getting it wrong. the description didn't say anything about BDSM but simply implied the seme is a sadist and when you read the Manga you could tell that he really is! I mean he sort of mislead the uke and manipulated him in a sadistic way. if there was any BDSM it'd ruin this manga imo, it's good aND cute as it is ^^
There is no SM in this, the description is misleading. It's a very cute and fluffy story