First thing I notice, before even clicking on the link is that you have a typo in your summary! It should be 'Whether.' I also feel like your summary should be fleshed out a little more? Based on that alone, I'm not likely to click on the story because the title doesn't explain much, the cover doesn't explain much, and the summary doesn't explain much.
Skimming through the first chapter, I notice the main character isn't named until ~quarter way through the first chapter. Try to mention her name much sooner! Preferably in the first paragraph or two. It can help give a more immediate connection to your character.
There's one point where you say 'Our protagonist shook her head.' Replace 'Our protagonist' with Mikoto. Replace 'The long haired girl' with the characters name. Replace 'the shorter haired girl' with the characters name. (Here's a link, the top comment explains very well when to use epithets in writing https://www.reddit.com/r/FanFiction/comments/7sv1ot/using_minor_epithets_in_writing/)
Is there incest in this story? If there is then definitely tag and warn for it because that's not really something you should surprise readers with. The focus on 'biological sister' and her 'well endowed chest' gave of some kind of incest-y vibes, but if it's just that they're really close in a familial way then ignore me. If there's going to be a lot of jokes/mentions/vibes towards incest then tag it so people are aware before they click to read 
Again I just skimmed through the first chapter to see if anything kind of popped out that you might be able to work on
