Analysis:How Satoru Fell from the Clock Tower

In the prologue, Satoru ends up falling from the clock tower. At that time, there was the shadow of someone behind Satoru. Let's consider some candidates for the culprit who pushed Satoru down the clock tower.

If Enomoto is the culprit
It is persumed that the stairs leading to the clock tower are found in the room with Enomoto. That makes Enomoto a primary suspect.

However, Enomoto is upset that Satoru lost his memories. He says "I should've never let you go up the clock tower" if he knew it would result in Satoru losing his memories. If Enomoto is actually the culprit, why would he regret him "climbing the clock tower"? Wouldn't he regret having "pushed him off" instead?

If we believe what he says, he is not likely the culprit.

If Utsumi is the culprit
There's no clear reason why she would have pushed him. In fact, it would have some conflicts with her plan to exterminate those who get in her way.

Given that her method of climbing the clock tower is unknown, she can be excluded from the list of culprits.

If Yuni is the culprit
Yuni, on the other hand, has a motive. He wants to recreate the events of SPHIA in 2012 in order to rescue everyone in the cabin. Kokoro and Satoru come and go between the cabin and SPHIA. If SPHIA's history is changed, Kokoro or Satoru's actions in the cabin would also change which may change the history in the cabin.

However, on the 1st day of Satoru's route, Yuni seems disappointed that Satoru lost his memories.

Even if Satoru hadn't lost his memories, it may still possible to execute the YUKIDOH plan as long as Satoru and Yuni behave in a way to recreate a similar history.

Thus the possibility of Yuni being the culprit is not that high.

If Inubushi is the culprit
Falling from the clock tower causes the consciousness of [ORE] to take over Satoru.

In order to descend and take over Satoru's body, it's possible that [ORE] causes the culprit to act. [ORE] and "Shadow" are two parts of the player, and "Shadow" exists within Inubushi, so [ORE] could have influenced "Shadow".

The fact that there was emphasis on the word "shadow" referring to the figure that appeared in the prologue may show that she is the culprit.

However, it's not known how she climbed the clock tower, and it's doubtful that Enomoto would let her go up.

Another person is the culprit
Let's take another look at Satoru's prologue.

Satoru sees the shadow behind him and steps back. The scene changes. When we return to the scene, Satoru is already falling.

We don't see him being pushed off the tower directly.

Did the shadow really push Satoru? Isn't it possible that he simply slipped off?

If that's the case, the person who pushed him off from the clock tower is Satoru himself.

If that's the case, what cast the shadow behind Satoru? Considering the nature of the story, it shouldn't come as a surprise what the true nature of the "shadow" is. It makes sense in its own way.

There is one likely person. It's the player themselves.

Since the YUKIDOH plan is designed to trap the player, isn't it possible for Satoru to sense the shadow or presence of the player? Isn't it possible that the player's own shadow was projected into Satoru's eyes?

Even Kokoro feels the shadow in some of the bad ends. "I felt it. Behind me was the shadow of the existence that had beckoned us into this situation. In the evening... lit by the dawn... It had neither volume nor mass. ――A point. A hollow nothingness."

It seems Satoru only realized the shadow's source at the end.