In order to decipher complex geological history of a planetary body, it is essential to integrate the global remote sensing data and laboratory analysis of the returned sample. Earth's Moon is the best example to demonstrate this synergy because we have both a large collection of lunar samples and tremendous amount of remote sensing data obtained by recent lunar exploration missions. Reanalysis of archived Apollo samples revealed that the Moon has preserved water in the interior, while the traditional scenario of the Earth-Moon system formation, known as “Giant Impact,” leads to complete loss of volatile components. The global data sets provided by SELENE/Kaguya suggest that a leftover planetesimal of several hundred kilometers in size could have delivered water to the Moon just after solidification of the highland crust from magma ocean. Studies on the volatile inventory of the Moon will help us to understand the formation of Earth's ocean, atmosphere and life.