Season 1
Living in the shadow of his talented younger sister, Kyousuke Kosaka conducts a normal lifestyle until he accidentally finds out that she hides a secret. In addition to being smart, pretty, and popular; Kirino Kosaka is also an obsessive consumer of anime and eroge (adult computer games). What will Kyousuke do? Will this tear their already rocky relationship apart or bring them closer together?
01. My Little Sister Can't Be My Love
For years, ordinary high-schooler Kousaka Kyousuke has had an icy relationship with his younger sister Kirino, a star athlete who is also a star student.
02. My Little Sister Can't Bring Me to an IRL Meet
While being grilled by Kirino over why he hasn't made any progress in the game she ordered him to complete, it occurs to Kyousuke that she needs some friends that she can talk to without concealing her otaku interests.
03. My Little Sister Can't Be This Cute
Kirino finds her first otaku friends at the IRL meet: "Kuroneko" and "Saori Bajeena." They spend their days deep in discussions over their otaku interests. Seeing Kirino this way puts Kyousuke's mind at ease.
04. My Little Sister Can't Be Going to Summerket
One day, Kirino's non-otaku, "public" friends—Aragaki Ayase and Kurusu Nanako—come over to visit. Kyousuke is harshly told by Kirino to not let her friends see him.
05. My Little Sister's Best Friend Can't Be This XX
On the way home from an enjoyable Summerket. They bump into Aragaki Ayase, Kirino's best friend.
06. My Childhood Friend Can't Be This Cute
Kyousuke is asked about his relationship with Manami by his friend, Akagi. Akagi is exasperated when Kyousuke answers that, although they don't have a romantic relationship, he doesn't want her to be taken by anyone else.
07. My Little Sister Can't Be a Novelist
Kyousuke comes home one day and is startled to find Kuroneko loitering in the living room by herself.
08. My Little Sister Can't Be Animated
Kirino has made her debut as an author. Reader response has been overwhelming, and her editor has even better news to report.
09. My Little Sister Can't Be This Absorbed Into Eroge
Kirino has been acting strangely antsy for the past few days. The reason is that the little sister game she ordered hasn't arrived yet.
10. My Little Sister Can't Be Cosplaying Like This
One day, Ayase calls Kyousuke out of the blue and asks him to see her. She wants to get Kirino a present, and wants him to think of what she would be happiest to get.
11. My Little Sister Can't Be This Maid
Sent out to buy groceries by his mother, Kyousuke bumps into Manami at the supermarket. They get to talking, and they eventually arrange for Manami to come visit for the first time in ages.
12. My Little Sister's Advice Can't End Here (GOOD END)
Ever since the events of the previous episode, Kyousuke has been nervous about his improved relationship with his sister.