Kono Naka ni Hitori, Imouto ga Iru - ep04

In the aftermath of what happen last time, Shougo believe that he knows who his sister is but wants to be one hundred percent certain of it. This is why Mister X is going through all the possible voice changers, that if they find a match it might be possible to find the person calling him through the paper trail. Then with the additional information that Shougo gives Mister X that it is water proof as well as being small. Since one time she call him while taking a bath, this gives Mister X something more to use to narrow his search by.

Then while Mister X is continuing his search, Shougo goes to class. Although while in class Konoe gets concerned over Miyabi change in behavior. Which is why later she confronts Shougo about it. Since Shougo feels that he is correct in his assumption that Miyabi is his sister, he confides in Konoe about everything that has been going on. However later when he returns to class he finds to Konoe is gone, then once school is out he receives a call from Mister X about to voice changer. That the model was made but all were recalled because it was too good at what it did. That means that the only one that could have been used is to prototype. This point to the fact that Konoe has been the one calling him that the connection to Miyabi was just a misunderstanding.

Then in his desire to find and confront Konoe, he recruits various people from around school to help him like Mana and Rinka as well as Miyabi. Then once he leave the school he tries to think of all the place that Konoe might go, that leads him to the park. Which is one of the first place they went after the meet for the first time. Once there she explains to him that she felt guilty for not telling him sooner since he was so honest with her. This leads her to tell him about when the photo was taken, however this cause him to understand something. That all this time she had been calling him she wasn't meaning an actual sister but someone that was close enough to them that they consider them family. That the situation just snowballed out of control when one misunderstanding built upon another.

Then when they are about to kiss, Miyabi breaks them up by complaining getting her to help when he already found Konoe. This leads to Miyabi clearing up the misunderstand that she help create because she misunderstood what he meant back at her dorm. She thought that he remember the time when they were playing as kids and they had a pretend wedding. That he was making reference to that, however once he explains what has been going on with him. Miyabi can understand his overall confusion. Then for a while he is relieved that he doesn't have a hidden sister, although when questioned them about which one call out to him at his fathers funeral. They both answer in their own way that neither of them went. This means that he still has a sister out there, it just means that it is neither Miyabi or Konoe. Questions is if there really is one, where is she. The only thing he know for certain is that it is safe for him to date Miyabi or Konoe.