Tobioriyou to Shiteiru Joshikousei wo Tasuketara Dou Naru no ka?

Synopsis

The start of a happy life together with a high school girl who has fallen into the bottom of despair. One day, Yuusuke Yuuki, who spent his high school life only in studying and working part-time in order to maintain his scholarship, found himself strongly wishing for a girlfriend. On the way home, feeling lonely from such thought, he casually looked up into the sky and saw a girl who was about to throw herself off the rooftop of an abandoned building. "Why the hell are doing something like this!" "Because I...don't have any...reason to live..." "Wait. It'd be a shame for a beauty to die" "....?" "Rather than dying, be my girlfriend" "Eeh?" Thus, a new love story and daily life with a mysterious girl, Kotori Hatsushiro, which all started from a strange encounter, begins. (Source: Kadokawa, translated)