Very interesting beginning and I like the idea that even with as different as Sesshoumaru and Inuyasha are, they basically have the same reactions to Buyo hehe.  Word of advice though, I would suggest working in third person instead of first, he/she instead of I, since writing first person Sesshoumaru is really difficult and it takes a bit away from your story.

Wow, what a cute, sweet story.  I loved the interactions between Sesshomaru and Mayo. And the thought of what Sesshomaru looked like after drinking the soy milk and started feeling the effects is hilarious.  Great job.

My sides hurt! I thought this was amazingly funny. Although sometimes I'd have to say Sesshomaru acts like the cat! And watch certain terms... saying that someone has hissed something relatively explanitory, but given the subject of this story, saying that sesshomaru has hissed something to Buyo or about him, is a little confusing. Also, Dokuga rules are no Authors notes as chapters. I'd advise adding the chapter 6 AN to the end of your update on chapter 5. Great work, and very funny.

First off I want to say that this is indeed an interesting tale you are weaving, I did burst out laughing several times at the perdicaments you put Sesshoumaru through, I never thought Buyo was so evil...lol... It does however leave the burning question of how Sesshoumaru ended up staying with Kagome, and if they are not mated why he puts up with her in the first place?

However there is a rule on Dokuga that you cannot have AN's as chapters by themselves so you will have to edit chapter 6, other than that I believe you have a great start here, and I will look forward to more of your work in the future.