Chapter 12.5
This is a 4-koma featuring the high school kid Kei, and his childhood friend Rin, who loves paper airplanes. Kei seems to like Rin, though he's somewhat oblivious to his own feelings. With the addition of Rin's classmate Ryuusuke, who shares her love of paper airplanes, and another new character, Aoi, Kei's emotions become more and more complicated. Apparently feelings, like paper airplanes, don't fly straight.
Chapter 3.5
Yuuki Hase desperately wants to be friends with Kaori Fujimiya, the girl in class who seems to always be alone. Just when he thinks they've hit it off, she tells him her secret: Every week, her memories reset. Yuuki resolves to befriend her as many times as it takes, but is he prepared for how much it will hurt to be one-week friends...?