well, the cat was not for adoption in the first place, they just found it in the box, before a shop, no paper or something like that indicate someone put it here for adoption.
miko and co just found it here and assume he was abandoned, but as hitoe say in the chapter 63, the kitten love to sit in front of the shop, that the reason she put a frame in the street in the end of the chapter 63, and there was no collar, so for anybody passing there, it's just a stray cat.
hence the confusion in the first place.
and it's not like the author looooove to put foreshadowing thing in the manga, the "haunted ikemen", "godmother" or even "rom the psychik" appear long before the author decide to explore their story.