Imouto sae Ireba Ii.

Summary

Hopeless siscon Hashima Itsuki, our protagonist, is surrounded by many different kinds of people: first class genius and lover, the high-end unfortunate beauty Kani Nayuta; troubled about love, troubled about friendships, troubled even in her dreams, victor of the three crowns Shirakawa Miyako; brutal tax sabre, Oono Ashley; and natural-born illustrator, Puriketsu. Each and every one as hesitant as the next, and each and every one dealing with their own headaches. This is a busy story of a group of bewildering characters that play games together, take trips together, and work together-never a single dull day. Watching over them is the kind and thoughtful, completely perfect, superhuman little brother of Itsuki; Chihiro, with a huge secret of his own― (Source: Baka-Tsuki, edited)