|Also known as||Risa, Sphinx #3|
|Birthday||March 7th 1998|
|Physical and Vital Statistics|
Lisa is a quiet girl who is easily bullied due to her clumsy behavior and introverted nature. Her introversion makes her keep her problems to herself and usually resent the outside world. She feels she has a connection with Sphinx duo, and feels that the three of them share the same disconnection with the world. Despite her initial setbacks and doing dangerous operations with them she still chooses to keep on living, showing that she has plenty of courage and perseverance. She also seems to be quite clumsy, burning and dropping food, and also activating cellphones detonators by touching them accidentally.
Lisa is a girl of average height and frail, pale appearance. She has short, jet black hair and brown eyes. She is mostly seen wearing dresses or girly outfits.
Her father and mother are divorced, and her mother is over-protective and appears to be mentally unstable. She holds the fear that Lisa would also one day leave her just like Lisa's father did.
- The 三 in her name (三島 リサ) means three. She is the only character that has a number in her name, but doesn't have anything to do with the institution that Nine and Twelve were in.
- Lisa (リサ) means "to help or support again" while Mishima (三島) means three islands.
- The difference between the numbers 12 and 9 is 3. If worded to fit the anime, Lisa is different from Nine and Twelve because she wasn't one of the children in the institution, despite having a number in her name. Another way of wording is that the difference between Twelve and Nine is how they treat Lisa throughout the series, and their opinions of how to protect her.
- Her name can symbolize the foreshadowing of the three surviving children from the Settlement to die at the end of the series.
- She is called by her first name by Nine and Twelve without any honorifics. This is very uncommon in Japanese culture, as this would only happen if the three were friends, which they weren't in the beginning of the series. It could be that both Nine and Twelve hoped to be friends with her in the end, which they did.
- A popular fan theory had been circulating the web during the airing of the show that she was related to Shibazaki. This was due to the fact that Lisa was without a father, and Shibazaki stating he hasn't seen his family in a while. This is later proven wrong when Shibazaki is seen with his family.
- She is nicknamed Sphinx Number Three by Nine and Twelve. However, this is only once and that was in episode 7.
- According to Twelve, her voice has a pale yellow colour, which is rare.
- She has been commented to have the "same eyes as the children in the institution".
- She can't cook. (As can be seen in episode 5, when she burnt their food, and episode 8, and when she is putting strawberry Pocky in the curry.)
- She is terrible at soccer. (She couldn't head butt or kick the ball, as can be seen in episode 11)
- She is the only one out of the three protagonists to survive in the end.
- Her birthday is on March 7 1998.