there's a specific background with the cage in it?! actually i wonder how toma bought back such a large cage without catching other's attention lol

Yup, I read the summary and I thought it was really funny and weird that her heart will shatter from beating too fast. XD the plot sound something like an Aya Shouoto harem shoujo. (author of Barajou no Kiss & S.L.H) And lol, cheesy! I hope I will be able to play the game someday.