I think that is Yuuka's redecorating and landscaping services. Though I think Yuuka just hated the wall and thought to bring in more moon light for Flan. As for the the land on the other side and the mountain. Eh...they blocked the view.
…the repair will be deducted from your payBut rather than doing painful things, let me teach you something to make our hearts throb.…if you have no business here, just go home now, LadyNice to meet you. I am Kazami Yuuka. Good to know we can get along with each other.