Funny, just today i started to read it all again from the beginning and suddenly i decided to see if there was a new one today. The last one i was reading? This one: http://danbooru.me/posts/317297?pool_id=675
It's more like she wanted to tag along for fun. Then Rin had to poke into Haku's business and get her involved, too. So Chibi Miku's all like, "Awkward...".