The song is friends of the sand from Children of the Whales.
lyrics Sajou no tomoyo itoshiki tomoyo tenohira suna o miyo koko ni ikuoku-mono hikari ari ... anata ga hikarabi hitsugi ni sono mi o yuwae rare inishie no shinkai no naka koboredomo kinki no sono ni kaatoku ikin sajou no tomoyo itoshiki tomoyo sajou no tomoyo itoshiki tomoyo itoshiki tomoyo
