One Week Friends Vol. 4 (manga)

Even though Kaori's memories were washed away each week, it was clear that Yuuki remained tucked away somewhere in her heart...or at least, that's how it felt before. Having Kaori treat him the way she did that very first time they spoke is painful, but Yuuki isn't willing to give up on their one-week friendship - even if it means confronting Kaori's childhood friend, Hajime. Meanwhile, when Saki demands that Shougo own up to her reliance on others, things might start to change between the two of them...