Orphaned at a very young age, Gui, a fourth-year engineering student, has had to work hard and earn for himself for as long as he can remember Still, through the test of time, he still has a soft demeanor and a smile on his face Solo, a freshman in the Faculty of Music, can get anything he wants with a flick of his wrist Money, fame, good looks, the boy has everything, except his smile When Solos mother passed away, she took with him his smile Nothing could fill this missing hole in him that is — until one day when he sees a smiling boy working at a cafe One night the two worlds collide in a small coffee shop For a cup of hot milk and a warm smile, Solo finds himself back in the cafe every night For a soft boy who reminds him of a husky, Gui finds himself waiting for a late-night visitor with a cup of hot milk, night after night Night after night, the two boys continue to meet At the same spot, at the same time, until they soon come to realize that they have become each others breath A necessity Just like Oxygen