"Tsukimi or Otsukimi, literally moon-viewing, refers to Japanese festivals honoring the autumn moon. The celebration of the full moon typically takes place on the day of the eighth month of the traditional Japanese lunisolar calendar.
Tsukimi お月見 - Tsukimi means "moon-gazing". It's a Japanese custom to enjoy and appreciate the beautiful mid-September full moon, by offering Dango (dumpling) with pampas grass to the moon. /Now I understand "Serena Tsukino"