Theory:Itsuki Tachibana

Theories

Theory	Citations	Notes
Sae Kurosawa liked/cared for Itsuki.	Official wallpaper art of the two spending time together.	+ Sae looks back one last time at Itsuki as they run away from Minakami Village + Sae explicitly wishes to visit Itsuki one more time before the festival. + Sae cries and blames herself for Itsuki's death. - Itsuki was her friend and she would have mourned his death no matter what. - Yae mentions Itsuki more often than Sae does in their shared diary.
Itsuki liked/cared for Yae Kurosawa.	Yae mentions Itsuki a lot in her diary.	+ Itsuki and Yae would both have been Remaining. - Being a Remaining does not make a basis for a relationship. - Yae doesn't look back at Itsuki when he helps them run away from Minakami Village - Yae shows obvious interest in Ryozo Munakata when he is welcomed to the Kurosawa House in a game cutscene.