After Being Betrayed by My Girlfriend, I Kiss Her Little Sister

On Christmas Eve, I, Kanata Miyauchi, has been betrayed by my girlfriend, who is also my childhood friend.

After I finished shopping at the mall, on my way back home, I saw Umi holding hands with some guy I don’t know.

I’ve known Umi ever since I can remember. She is the most important person to me in this whole world.

But why…why did she do this to me?

How could she ever cheat on me behind my back…