Wow, this is really something else! I came here with the promise of a mermaid, but reading it, it just makes me want know more! I mean, is Gina really a mermaid that has lost her memory (An idea explored in a fanfic: http://www.fanfiction.net/s/5312895/1/bBetween_b_the_bOcean_b_and_the_Sky )? As of right now, we don't know.
I'll give the chapter 89/100%, minus points for short length and abrupt ending.