Responses
Yes there are 5 ghost including Touma. The key is you need to look at their pupil shapes. The one who possesed Yuuma to give the letter was indeed Touma. Touma was that biggest eye who always looked at them so angry and in the panel that shows the past lives, I think Touma wasn't there, that just only his reborns, that's why it's 4. I think the last ghost is still there, we just haven't see him appear again bcz y know his goal was to see them having sex to finally find peace, so I think he will reappear in the next chapter
So that 4th ghost, that wasn't Touma, right? Because he said he didn't possess Yuma during the letter thing, so that was Touma that did that and not the 4th ghost. So there's actually 5 ghosts? Then where is it now? Or was it lying? Is Touma actually that 4th ghost? The panel where it showed the past lives, there were 4, but in some scenes we also see some other entity looming over them.