“All I need is my brother. That's what I thought ――.” The twin brother Zen hates his older brother Sho's lover. One day, the two of them meet Sho's boyfriend's younger brother, Kaito. The love between two brothers is shaken, a square relationship love!

A world where only twins are born as a result of genetic modification to stop population decline. One of the twins is born in the form of a beastman, and the twins end up sharing some kind of feeling. For example, the sense of smell, taste etc. are shared by each twin, and these are called "synesthesia"

Perhaps because of this ''synesthesia,'' this work also has a very close depiction of the relationship between twins.