Kobato, Volume 1 — CLAMP

Meet Kobato Hanato, a sweet and rather simple young girl on a quest to
have her single, dearest wish granted. But first, she must learn the
ways of the world from Ioryogi-san, a gruff blue dog whose bark is just
as bad as his bite! Under his "tutelage" (read: constant verbal abuse),
Kobato puts her efforts into passing various trials of common sense so
that she may obtain the key to getting her wish-a magic bottle which
must be filled with the suffering of wounded hearts that Kobato herself
has healed. But with Kobato's common sense sorely lacking, she keeps
flunking Ioryogi-san's trials left and right! It looks like the road
that lies ahead of Kobato will be a long one indeed!