To LOVE-Ru Darkness: Little Sisters

Four short stories about adventures of little sisters:

Stray dog ~Leave it to Nana!~ (Nana ni Omakase!)
Paper doll ~Changing doll Mikan~ (Kisekae Mikan)
Family trouble ~Yui's papa is shamless!?~ (Yui no Papa wa Harenchi!?)
Secret feelings ~Momo and angel's flute~ (Momo to Tenshi no Fue)