Ore no Imouto ga Konna ni Kawaii Wake ga Nai Things

Cat Ears are often seen in anime/manga on cat-like characters or in cosplay. They can be either natural or artificial in nature.

Dakimakura is a portmanteau of "dakishime" (hugging) and "makura" (pillow). They are body pillows featuring (mainly) female anime characters and are meant to snuggle with.

A Kimono is a traditional piece of Japanese clothing that is worn by women, men, and children alike. They are normally long robes with long and wide sleeves.

Lunch boxes are traditional in Japan for taking to school and work, sometimes they are given as a sign of admiration for someone.

The character is wearing school uniform. Most probably he/she's a student.