Kaori Fujimiya is always alone because all of her happy memories, including time spent with her friends, disappear every Monday. Deciding that he wants to be friends with her anyway, Yuuki Hase tries to get close to Kaori each week, wishing that she would one day call him “a friend”.

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. Note: Since this is volume 1, the manga may or may not be continued.