Bunny Girl: North of the mermaid lake, there is a house, you need the town key to enter (obtain at the starting town's mayor house's bookshelf at night), that's where the Bunny girl live, talk to her and she will be sent back to the bar, talk to her upstair at night to start the scene.
Secret Nun scene: After clearing the game, view Jenna's peeping event in the mountain village. During the event, when the peeping man exclaims, 「でたぁ!!ス スゲェッ!!」 "Whoa!! Amazing!!", wait without pressing any buttons. After a while, the screen will change, leading to Jenna's hidden event.
The guide said that but basically you need to see that the peeping tom said "Whoa!! Amazing!!", press button ONCE so that the text box disappear, then wait a while to start the hidden scene
also the link to the full game ya give need Mediafire Premium to download lol