No matter how you look at it, the Inubushi in the last scene is the personality of the original Inubushi Keiko. In that case, is the real Suzukage Hotori’s consciousness trapped on the mountain? Let’s look at some possibilities.
Was Hotori swallowed up in the avalanche?
On the 7th day of Satoru’s route, during the avalanche scene Inubushi still feels like Suzukage Hotori. At this point, she can talk. However, once she’s swallowed up by the avalanche, she falls into a daze. When Kokoro is asking her questions she’s silent, only responding by nodding or shaking her head. Doesn’t this seem like Hotori?
Her personality before and after the avalanche
Let’s think about what’s happening here. First of all, at 4:40 AM on January 17th, SPHIA is transported to Mt. Akakura. At this point, Inubushi and the others’ consciousnesses are left behind, and the personality switch occurs. As usual, Hotori’s consciousness — which is on Mt. Akakura — enters Inubushi’s body. Inubushi’s consciousness is in the white underground facility, which just got transported to Aosagi Island. However, there is no body for her to inhabit here as the twins are outside the circle along with Utsumi. Therefore, for these 33 minutes, Inubushi becomes nothing but a consciousness.
And then, Hotori and the others and Mt. Akakura get swallowed up by the avalanche. The fact that she is able to speak her is likely because she recovered from her aphasia. She only speaks three times during this scene so I can’t say for sure, but the way she talks feels a little different from Inubushi. Unfortunately, after the avalanche, the shock causes Hotori to lose her voice again…
During that period, several transfers occur, but since they are outside the circle, Hotori’s consciousness remains in Inubushi’s body. Inubushi’s consciousness is left at Aosagi Island with no body to inhabit. Then, Hotori returns to SPHIA, which is at Mt. Akakura. The next transfer takes SPHIA to Hotarubi. However, no one’s consciousness is left at Hotarubi. If Hotori’s consciousness stayed behind during this transfer, Inubushi’s body would be left empty. In order to prevent that possibility, it is conceivable that this time Hotori’s consciousness goes along with the body.
Satoru and Kokoro never actually see Inubushi’s body without a consciousness, but since Hotori was holed up in her room, they could have just missed it by chance. However, it’s likely that she was tending to the wounded Yomogi and Kokoro and followed Yomogi’s instructions to prevent frostbite during this time. It would be strange to think of her being in her room for 33 minutes.
Finally, SPHIA transfers to Aosagi Island. Let’s say that Hotori’s consciousness stays with her body at this time as well. If her consciousness stayed behind then it would have no body to reside in. At this point, you might think “But Inubushi’s consciousness already doesn’t have a body.” However, that was allowed to happen because Inubushi is a part of the player’s consciousness. Hotori is not directly connected to the player’s consciousness, so it would be unnatural for her consciousness to remain in the world without a body. Therefore, her body started moving together with Inubushi’s body.
Inubushi and Hotori
When SPHIA returned to Aosagi Island, Inubushi’s consciousness probably tried to return to her body. However, Hotori was already in her body. Even still, it needed to return. Inubushi, who had DID from the start, incorporated Hotori’s personality into her body.
After that point, no more transfers occurred. From then on, Inubushi’s original personality became mixed with Hotori’s, and she would probably switch between them like the typical symptoms of DID. Hotori may have lost her body, but her consciousness was able to survive.
Whether or not you believe this is up to you. After all, if there isn’t a logical explanation, wouldn’t you rather believe the most romantic option…?