Krystal's Links
She is Calvin's older sister. She cares about him, although the two don't talk to each other due to Calvin's shyness and their completely different interests.
He is Krystal's younger brother. He's too shy to talk to her very often, but still cares about her because... well, she's his sister.
She is Noel's younger sister. She cares about him, but doesn't talk to him often, due to them having completely different interests and him apparently being so busy that he doesn't have time to see his family. Because of this, she can't help but wonder if he's hiding something from her...
He is Krystal's older brother. He cares about her because she's his sister, but the two don't talk to each other often, due to them having completely different interests and him apparently being so busy that he doesn't have time to see his family.
She knows him as her older brother is close friends with him. She doesn't know him very well, but is friendly towards him because he must be a nice guy if he's friends with her brother, right?
He knows her as he's close friends with her older brother. He doesn't know her very well, but is friendly towards her as she's his best friend's brother.