You can’t give what you don’t have.
At the start of this story, Artemis was a simple girl, working in a café that Rhia’s father owns. She fends off for her family and never even once did she ask Rhia to buy her or her family anything because she doesn’t want to look like she’s taking advantage of her girlfriend’s wealth. She doesn’t see herself as someone worthy of a person as perfect as Rhia but she loved the girl so much that she just did her best to make her happy. That was before the accident. After the accident, Artemis lost her sight. She was devastated. If before, she looked at herself unworthy of such a perfect girl, now, she perceived herself as a rug in front of Kwon Rhia. She lost her sight so that means, she could no longer work and earn a living for her family. She felt utterly useless. And it even pained her more to think that Rhia would be taking all burdens on her shoulders. Knowing Rhia, she was quite sure that the girl would fuss over her day and night, would provide for her family and would pay for her operation. Things she doesn’t want to happen. She hates herself, fate and the world. Right there and then, she made a decision. She would prove to herself that she’s not useless, that she can do something, that she would not be a burden and that she is worthy of Kwon Rhia’s love. She asked Jaejoong for help because she knows that it would be the only way for Rhia not to look for her. She had to earn money and look for a donor thus, the 5-year gap.