Isshuukan Friends.

Synopsis

Kaori begins making lunches for Yuki and records what he likes to eat. Afterwards Yuki suggests that they let Shogo in on her secret for an outside perspective. The following day Yuki has Shogo join them for lunch and his harsh demeanor slightly intimidates Kaori. However Shogo seems to understand when Yuki begins to explain Kaori's memory loss and even provides theories on how it may have originated, despite his skepticism which creates a small rift between him and Yuki when the latter defends Kaori. The next day after school, Kaori forgets the diary under her desk and finds herself scared to retrieve it in front of the other students, especially when two girls bring her to tears with their trash talk of her. However Shogo retrieves the diary for Kaori and explains that people won't understand her if she doesn't speak to them herself. The following Monday, Yuki runs after Kaori when she rushes out of class after a Math problem suddenly causes her to remember the eggs she made for lunch the week before. Shogo also follows them and since Kaori does remember him in the same manner as her family, deduces she doesn't consider them friends and ends up believing her story—with Yuki more optimistic than ever about Kaori's progress.

(Source: Wikipedia)