Chisato Mera (目良 千里, めら ちさと lit. Mera Chisato) is a classmate of Kusuo's. She works part time in Cafe Mami as a waitress.
Chisato sports maroon hair tied into two low bunches with colorful beads. She has maroon eyes and wears a pair of round spectacles with a piece of lens missing. Her PE Uniform and swimsuit had other people's name on it as she could not afford to buy new ones. She is described to have a starved appearance.
Chisato is a clumsy girl that frequently breaks dishes and gets hyped whenever food or money is being talked about. She works hard for her family, taking on multiple jobs to support them, and possibly skipping meals so her siblings could eat as she stated that the ramen she was having at school after winter break was the first meal of the year even though it was the 20th of January and over summer break she ate mostly grass. Because of this she'll eat anything if given the opportunity including taking handfuls of food samples and the burnt remains of failed cooking class attempts. Mera can survive very well, as was displayed when the group of friends were stranded on the island.
Chisato's family used to be rich but due to a sudden debt crisis, their family sunk into debts and loan sharks took everything and now they are very poor. Because her mother is sick and she has a lot of younger siblings, she has to work more than one job. Not much was exposed about her family but it was said that she has a lot of siblings and is low in financial support. Three siblings can be seen in the anime right before the Okinawa trip, twin brothers and a younger sister, comforting her about not being able to go, before getting a ticket.
Her main diet is beansprouts, bread crumbs, grass or snow depending on the season.
Mera's name uses the same Kanji as the Japanese for clairvoyance (千里眼, Senrigan).
She represents "Gluttony" out of all sins, proved by the point where she can consume any type of food, namely raw, overcooked or even rotten. Mera, like a glutton she is, will use any method to obtain food. She basically extorted food from her classmates when her birthday arrived, despite giving them a single acorn on their respective birthdays.
Episode 20 shows her gluttony get out of control. After Saiki's cooking partners kept screwing up crepè cooking, she ate their failed attempts. When Saiki attempts to cook himself, he find Mera stole the remaining batter and is slurping it down; oddly she does not get reprimanded (even via Saiki manipulating their teacher).
Due to her obsessive greed for food, she can change into another species altogether sometimes when desperate. She changes into an Amazon during the shipwreck with her classmates. She can be quite selfish even to her classmates, shown by the fact that she stole all of the food supplies from the wrecked ship without her classmates' knowledge. She did salvage some mushrooms for them, although it's barely edible.