Episode 5 has one of the most honest and heartfelt apologies in fiction. That it comes from someone you don't expect it from, and over something that is really rather trivial only adds to it.
Episode 8 shows Momoyo battling one of the cyborg girls and getting really worked up on it, yet every now and then the scene switches to that of Momoyo walking around the city with a glum look on her face. Then the music changes from that of an action song to a melancholy one (with the scene change continuing), before things really hit the fan when one of the missiles fired by the cyborg and deflected by Momoyo hits Yamato. Cue scene change to the hospital, where the other girls are already there (with Miyako on her hands and knees) as Momoyo walks towards them wearily. Then she sees Yamato in a coma in the ICU before she lets out a Skyward Scream.
Episode 10: Yamato is knocked unconscious during another battle with the cyborg girls, who are eventually driven off. The girls feel their heart sink at the prone Yamato and end up spilling out their feelings for him. Then Momoyo really loses it, shoving the other girls aside while declaring Yamato to be hers alone. Mayucchi then refutes Momoyo for rejecting Yamato's feelings when he confessed to the latter, thus making things moot for Momoyo, and Mayucchi continues berating Momoyo until Momoyo gets her resolve back.