It is said that one of the qualities of a true friendship is to understand and be understood. Unfortunately, this can be easier said than done, particularly when it comes to being friends with someone that has no recollection of being your friend the week after befriending them. To become friends over and over, again and again… that is the goal of Yuki Hase when approaching schoolmate Kaori Fujimaya. You see, things aren't so simple when your memory disappears. And that's exactly what happens with Kaori – she's always alone because she can't commit anything to memory, even if that commitment is as special as a memory of one of her friends. No matter how cherished her memories are, they vanish by the time Monday rolls around. But Yuki won't give up in the fight for friendship as he embarks on a new mission every week to befriend a person he already knows.