Humour in the manga currently comes from how hard Masato tries to avoid running into her and ignores any news Itsuki tells him about her. Masato still refuses to admit he has any secrets to tell her which means the harrassment continues.
I have no idea why I feel so apathetic about the plot. I think I feel as resigned as Masato does about Miyu's interference.
Chapter 2 she handcuffs herself to him and hides the key and then slips out of it and leaves him stranded at the end of the day.
Chapter 3 Masato enjoys a Miyu-free school day when she is surprisingly absent. Turns out she was sick (according to the ever concerned Itsuki) but she still escapes from the doctor and corners him at the end JUST TO TELL him that she won't give up on getting an answer out of him. Masato is partially successful in acting apathetic when he receives the news that she was sick though he does try to look for her when he hears that someone has collapsed on the road like in chapter 1 (it's someone else though).
Chapter 4 It is shown that Miyu is rich and she doesn't listen to her mother. Masato has a fan club who try to defend him from Miyu's harrassment. When they witness Miyu break Masato's nose for accidentally touching her (while she was trying to keep her notebook away from Itsuki), they introduce themselves and ask to talk to her. Miyu follows them thinking they can answer her questions on Masato [The questions are what is Chloe's biggest fear and weakness]. When they try to teach her a lesson on harrassing their hero, she beats them up. This puts to rest Itsuki's fears that she needs to be rescued by Masato and him. The girls she beat up also become her fans.
There is some mention of Masato acting out of character? or having strange thoughts? and then questioning himself on why he feels or thinks that way. Also, he seems to have developed a Miyu-detecting ability in Chapter 4.