The Lost Souls appear as a floating blue flame.
These Spirits simply float about in the places they have died, trying to find a way into the afterlife. They don't harm people or show any signs of malice or resentment.
In Yomawari: Night Alone, one of the Lost Souls died from being caught up in a car crash at the Town area where a road railing suffered a dent because of the car crash. The Protagonist can interact with the dented road railing to summon the Spirit and guide it to the nearby shrine. If she does this, it will go into the afterlife and leave the girl a Hard Candy. However, the girl must follow a specific route. She must go down the alley southwest from where she is. Then, when she reaches the intersection, she must go down until she reaches the main road. She must then interact with the nearby shrine to send the soul to the afterlife. If she doesn't follow this route, the soul will disappear and return to the dented road railing.
In Yomawari: Midnight Shadows, a number of Lost Souls will appear in the middle of the streets and follow Haru for a while. They will appear one by one until they form a crowd. They do not do her any harm if she touches them, but the Spirits will increase her Heartbeat System based on how close they are to her. After a while, they all disappear.
Mythology and Theories Edit
The Lost Souls are known as Hitodama (meaning 'human soul' in Japanese) in Japan. In Japanese mythology, it is believed that people's souls appear as a floating blue flame with a tail (though, different areas of Japan have different opinions on some of the characteristics of the soul, like its color or length of its tail). They're the souls of recently dead people. However, they're alo said to be found in graveyards or dark forests in summer time.
Hence, the blue flames that appear in the games must be someone's soul.
The Lost Souls are different from many other Spirits because these Spirits aren't hostile towards humans for a good reason. Unlike many Spirits, the Lost Souls aren't stuck in the living world because of being held down by sins or grudges. The Lost Souls are stuck there because they are having problems finding a way to the afterlife or have some incomplete business that isn't technically bad. These Spirits aren't tainted by resent or sins, though they may be restless.
In Yomawari: Night Alone, in the Protagonist's Town, one soul appears from a dented road railing, which is a sign of car crash. It is likely that this soul belonged to someone who died from that car crash. It is probably the old man that was mentioned in the note behind the sign board just pass the northern railroad (near the Field area). It said that an old man died from being hit by a car while heading to the shrine. This may explain why it needs to go to the nearby shrine, because that was where it was going when it was still alive as the old man.
As for the reason for not being able to take the main road to the shrine, it may be because of its dislike for the main road because it died in a 'car' crash. Or maybe it's because that was the path it took all the time to the shrine when it was alive. As for the other ways, it may just take too long.
In Yomawari: Midnight Shadows, Haru can find small crowds of Lost Souls in the streets of the Second Town. They will follow her for a while before disappearing, not doing any harm to her. However, there is no known reasons why they appear to follow her for a while and why they are haunting the streets of the town.
- The Lost Soul at the dented road rail is most likely the old man mentioned in the notes at the back of the bulletin board near the entrance to the Field and the northern railroad.