Okay, you've got some potential, but you've got a lot of problems here.
1. Hiromu Arikawa is female.
2. You have Samsu and Ed calling each other nii-san and nii-chan. This is a respectful term for an OLDER sibling only. Thus you've got them contradicting each other as to whom is older.
3. Samsu is a Mary Sue. Pure and simple.