  We will present main results of our recent investigations on the validity of
cosmic no-hair conjecture proposed by Hawking and his colleagues long time ago
in the framework of an anisotropic inflationary model proposed by Kanno, Soda,
and Watanabe. As a result, we will show that the cosmic no-hair conjecture
seems to be generally violated in the Kanno-Soda-Watanabe model for both
canonical and non-canonical scalar fields due to the existence of a non-trivial
coupling term between scalar and electromagnetic fields. However, we will also
show that the validity of the cosmic no-hair conjecture will be ensured once a
unusual scalar field called the phantom field, whose kinetic energy term is
negative definite, is introduced into the Kanno-Soda-Watanabe model.
