Koishi Uru Kagiri Koise

From BakaUpdates:

A series of short stories featuring "forbidden" love.

"Koi shiuru kagiri koise" (as long as you can fall in love, then fall in love) is like a Romeo and Juliet story.

"Soukyu no kakera" (a piece of the blue sky) features a story of a relationship between the son of the main wife and younger sister of the lover.

"Atashi no heya no oujisama" (the prince in my room) features a story of a scandalous cohabitation of a girl with her brother-in-law.

"Nigerarenai!" (can't escape) features a forbidden love between a sister and her younger brother.