Oh yeah, I responded to the OP before actually reading all the way through.
Anyways, actual thoughts on the first chapter! Honestly without this being tagged as yuri I would've thought that this would be the typical vampire romance manga with Rin and Yuunagi. However, I'm fairly confident that this particular story won't play out like that - for one thing, Matsumoto Tomoki wrote this and I really loved Prunus Girl so I'm pretty sure this will be nice too. I'll be looking forward to how this develops.
Also, the story itself has been atypical in Yuunagi's reaction to becoming a vampire, with her nonchalance (so far, at least) and the mood's light atmosphere. Another thing I like is that even though it's a comedy, the story seems like it could easily get more serious later on, and I really do love good Dramedies. Like, it's a more light-hearted take on a vampire story without it seeming like a completely crack-ish story. Does that make sense?
It's an odd thing to say what with the vampires and all, but this feels a lot more....*normal* than Prunus Girl. Like a more typical manga setting, which I guess is in keeping with Rin being a huge manga dork.
You can really identify the art style right from the beginning though.