You loved her, more than anything. You did everything for her, you lived for her, if there is any reason for you to live, it is her, Shu. And this connection was shared between the two of you for years, a love that you both had for each other.

But... why did Shu do that? What was the reason behind that action? That's the least of your problems... the girl you love and swore to always love is kissing someone else in front of you...