Well, You need to finish the Boy part first. And if you did it right then the girl part will be playable.
The fact is that I've already played the game for a boy 5 times, but the girl is so inaccessible to me. I kind of collected everything, I don't know English well, so I use a translator, but every time I take a screenshot, it gets boring. I do not know what can and cannot be selected.
At the moment, I have discovered 4 endings. One where it stays with tentacles, the second where it's like an evil ghost, the third if you use a talisman at the end and hug her, the fourth ending when you don't hug her, and the fifth at the end, it's also the first ending if you don't use a talisman.