I'm looking for a oneshot (it could've been part of another story's extra) where the shoujo protagonist loves her dog so much when she gets to her new school and sees a boy that resembles her dog she believes that he transformed into a boy because of how much she loves him. stuff happens and eventually she realizes he's a boy and she's in love with him etc. happy end.

Does anyone know which manga this is from?

Is it Hug! (FUJIWARA Yuka)?