It's definitely Tsukasa, the one talking to him is Hanako. But how he asks nene is she missing is really sus, it's like he is missing something. And also, who's that strange ghost near the window? I think AidaIro is going to reveal Hanako Tsukasas' background now. And I was thinking, what if, because the red house is cursed, something bad happens to Nene and she dies.
It actually adds up, Hanako died 60 years ago and the suicide of the family happened 50 years ago. Let's think that Tsukasa is 4 years old in that pannel and so if you add 10 years that would be 14, which will be the age for the second year of middle school.
Right?