Chaeyoung is diagnosed with a rare weak hearted syndrome.

Mina is a heart cancer patient.

Both became good friends upon living in the same building (Hospital) for few years.

I'm going to sleep now Chaeng.

"Minari..promise me we'll see the sun rise together tomorrow."

"Yes we will.."

With that both fell asleep with damp pillow from the liquid produce from their eyes.

That's their routine. 

Every morning will be a stroll at the park, sitting on the bench..fingers intertwined mesmerising the sun rise silently.

Every night the same phrase..

A promise to see the sunrise together.

A promise which themselves were not confirmed to comply or not.

Their due were getting nearer.

Mina life expectancy as told were 3 months from then.

Chaeyoung is 3years from then.

They were inseparable. 

They never spoke of the pain they're having but both knows of oneself disease. 

Sometimes it's intolerable seeing each others pain which suffocates the other half.

When mina is in pain she managed to held it until her body fails fainted on the ground while chaeyoung will be screaming for help and with her condition she can't seem to resist the stabbing pain on her weak heart turns out only to fall by mina side.

This happens almost twice or once a week. 

How can your own heart be so heartless.

They have their own world together. Even shared a bed together if mina saw chaeyoung shivering NOT from the obvious cold weather but from her rare type of heart disease. 

Chaeyoung shivering momentum easily fades whenever mina hug her. They being together is a perfect piece. 

According to mina's informer which is the nurse who's been attending chaeyoung, her condition is worsen by the time. Mina was ultimately shocked by that, since chaeyoung never tells her anything abou