Any interactions with Usami when Kyousuke and her arenīt chasing Maou is bound to have one or two.
Most of the meeting sessions of God!Kyousuke count. Particularly the one where Kyousuke plan his revenge on Kanon for the CD she broke.
The joke start to chapter four. Very impressive since it starts out as a crowning moment of heartwarming with Haru leaning against Kyousuke, asking him to not push her away. As he trips over his own thoughts and words coming to grips with the realization that she loves him, she continues to act moe as it gets until he finally asks her if she likes him, at which point she switches back to cloudcuckoolander mode remarking how warm he is. Kyousuke realizes she was just trying to get warm. The reader however might have to ask if that really was the only reason. To drive it home the have this playing the entire time.