大空寺危機一髪!

"If" story with Ayu and Mayu from Kimi ga Nozomu Eien. Main character works at a shop when walls start to be destructed by a strange bunch of people who want to create a new world. Protagonist falls in love with their leader Ayu from the first sight. He swears to protect her from whatever crazy enemies she might have. [From vndbreview]