Megumi Mishima (三島恵 Mishima Megumi) is the youngest daughter of Fusayo Mishima and Takanobu Mishima and the younger sister of Mayumi Mishima who is in the senior class of Yokosuka-dai kindergarden. She is nervous to go to elementary school and is always running around with Mayumi's old school bag on her back.
Megumi found an orphaned kitten whose mother was run over by a black car on the day Iwao Hazuki was murdered. Her mother would not allow her to keep the kitten at home, so she took care of it at the Yamanose Shrine. Ryo Hazuki is a good friend of hers. When she saw Mayumi and Ryo talking, she innocently asked them if they were getting married, and made them embarrassed. Later, she came to understand what "getting married" means. When she was asked by Nozomi Harasaki, "What would you like to be when you grown up?" she answered, "I am going to be married to Ryo!" This answer really surprised Nozomi. Later on, Fusayo allows Megumi to keep the kitten at home.
- Megumi's zodiac sign is Aries and she has a B blood type.