Isn't at page 11 the male MC referring to himself and not whoever "that guy" is? I can't check the raw because it still paywalled but going by the context of dialogues alone I'm probably right.
@GARE Isn't the kouhai already gone with the soccer guy. What made me think it's male MC line is because there's a sweat effect near the dialogue bubble so maybe the MC is self loathing.
@Kiriha to be fair they didnt depicted to go away, i thought they just chatting in a distance, and the sweat in dialogue bubble i think its just kouhai trying to get closer with popular senpai (highschool football club) with the topic she unsure its appropriate which is making fun of the MC.
This is just my thinking though, and the only things that makes sense to me.