Ruri Akutsu (阿久津 瑠璃 Akutsu Ruri) is the younger sister of Akuru Akutsu.
Ruri is a cute girl with armpit-length black hair that is tied in two pigtails with smiley-star pins and brown eyes.
Ruri is a hardworking elementary school student who devotes her time to studying and she is determined to become smart and dependable. Despite this, she utterly fails at nearly everything she does, which prompts Yoshiko Hanabatake to see her as a fellow "idiot". Much like Akuru Akutsu (Ruri's older brother), Ruri dislikes Yoshiko and she is mortified at the idea of becoming just like her.
Unlike Yoshiko, Ruri has a good amount of common sense, though sometimes her childishness will come out at points.
Akuru is Ruri's older brother. Due to Akuru seeming to have very low expectations of her and often tells her how it’s okay to be a failure, she does not like him too much.
While Yoshiko and Ruri both get zeros, but Ruri cares about her grades and Yoshiko doesn't care about her grades. Ruri is mortified at the idea of ending up like Yoshiko.
Ever since Sayaka encouraged Ruri, Ruri started to like Sayaka and seems to prefer her over Yoshiko. Ruri sees Sayaka as surrogate big sister since she has common sense and she is always kind to her when trying to help.
- The name Ruri means "Lapis lazuli" (琉璃).
- Ruri is blood type A.
- Ruri is 138cm (4'6") tall and weighs about 31 kg (68lbs).
- She was confirmed to be Grade 5, which meant she is 10. Later on, for her 11th birthday, Akuru gave her a book to help.