  We detected the H2O 6.3 micron bands in more than 30 normal red giants stars
from K5III to M8III as well as in some early M supergiants on the SWS spectra
retrieved from the ISO Data Archive. This result, however, shows serious
inconsistency with the present model photospheres which predict H2O only in the
latest M (super)giant stars. Also H2O was once discovered in the early M
(super)giant stars nearly 40 years ago with the balloon-borne telescope named
Stratoscope II. This discovery was so unexpected at that time that it was not
understood correctly and overlooked for a long time. Now, we reflect on our
ignorance of this important discovery during the 40 years and should consider
more seriously the meaning of the rediscovery of water in so many red
(super)giant stars with ISO. In view of the detection of H2O in emission in the
early M supergiant mu Cep as well as in late M giants with ISO, H2O should be
in the outer atmosphere rather than in the photosphere. We propose that the
absorption as well as emission of H2O should be originating in a new component,
which we refer to as molecular sphere. Since the extend atmospheres of red
(super)giants radiate efficiently in the infrared, it is not surprising if the
true structure of the atmospheres of these stars can first be revealed with the
infrared observations especially from space.
