Kawaii Kouhai ni Iwasaretai

The manga centers on Yasu and Moriyama. Yasu is Moriyama's upperclassman, but one day decides to ask Moriyama for romantic advice regarding "a certain girl." Moriyama gives Yasu the advice he asks for, although she does it by trying to steer Yasu toward confessing to her instead, in her own passive-aggressive yet deadpan way. In the end, Yasu ends up telling Moriyama that he loves her (the "certain girl" whom Yasu was talking about was indeed Moriyama). The story follows their mutually loving relationship, although Moriyama tends to get her way by bargaining aggressively with Yasu.

(Source: ANN)