Miyagawa Atsushi is an 11-year-old boy who is 180 centimeters tall. Since he has a grown-up looking build but acts his age, he has always been running into troubles. On the other hand, his 17-year-old elder sister Atsumi is only 137 centimeters tall. Even though she has a childish looking build, Atsumi takes good care of Atsushi. 

Episode 1 - Atsushi and Atsumi

Episode 2 - Atsumi and the Everyday

Episode 3 - Sayo and Atsumi

Episode 4 - Atsushi and Grade School

Episode 5 - Atsushi and the Bean-Throwing Festival

Episode 6 - Atsushi and Chocolate

Episode 7 - Movies and Misunderstandings

Episode 8 - Atsushi and the Doll Festival

Episode 9 - Take and Finding a Job

Episode 10 - Atsushi and White Day

Episode 11 - Atsushi and the Library

Episode 12 - Atsushi and Misunderstandings

Episode 13 - Flower Viewing and Siblings

Episode 14 - The New Students and the Misunderstanding

Episode 15 - Atsushi and the Bike

Episode 16 - Atsushi and his Dream

Episode 17 - Pastries and Cheering 

Episode 18 - Family and Hot Springs 

Episode 19 - Atsushi and Sports Day - Part 1

Episode 20 - Atsushi and Sports Day - Part 2

Episode 21 - Misunderstandings and Truth

Episode 22 - Atsushi and Hand-Me-Downs

Episode 23 - Atsushi and Culture Fairs

Episode 24 - Big Sister and Little Sister

Episode 25 - Atsushi and Chases

Episode 26 - Atsushi and Bye-Byes

Seven

Dream Creation

Recorder and Randsell