Ane no Shinyuu, Watashi no Koibito.(2021)

Ane no Shinyuu, Watashi no Koibito.

Sena is a novelist who has been dealing with romantic feelings for her sister, Yuuna. Upon learning that Yuuna is to be married, Yuuna's best friend and former partner Kiku asks Sena to be her lover.

Note: Chapter count includes four volume-bonus chapters plus one special chapter.