Imamiya Satoshi, also known as "Sasshi," grew up in Osaka's Abenobashi Shopping Arcade with his boyhood pal Asahina Arumi. All that was stable in his life is now in shambles. His family's spa house has closed and been demolished, and Arumi's family is relocating to Hokkaido with her. In the midst of it all, something happens to reality's framework, and Sasshi and Arumi find themselves in a strange parallel realm. It's still Abenobashi, but it's not theirs. Strange things are happening, and Sasshi must figure out what they signify in order to achieve a goal he hardly comprehends.