[No. 007] Harumi Yomoda's Drawing
A picture drawn by Harumi Yomoda, posted in the first floor corridor of the Oribe campus. In March of the previous year, Harumi lost her father Haruo and mother Hidemi in a lightning strike. Reflecting her brooding spirits afterwards, the picture is drawn in dark colours. The girl with black hair and the white dog-like creature on the right side of the picture are naturally Miyako and her beloved dog Cherub. It most likely shows her only friend, like she tells her teacher, Takato. However, it doesn't appear as though Takato knows of Miyako's existence until the scene when Harumi opens up to her on day 1, 23:00. At the time it was drawn, no one probably asked Harumi about who it was.
Incidentally, one of the other pictures on display in the first floor corridor is an actual drawing done by the beloved son of the director, Mr. Toyama.
[No. 008] Gojaku Field Trip Photo
These photos are posted on the wall of the first floor staff room of the campus. They show a group of children from the Oribe campus climbing Mt. Gojaku on a field trip, led by the principal, Nagoshi. Written on the back is, "a fun field trip with our nice principal nagoshi", and amidst the grinning students is Harumi, wearing a depressed expression. Principal Nagoshi also has his arm around Harumi's shoulders... From this photo, you can tell what an attentive teacher he was from the way he worries about Harumi, having lost her parents at such a young age. Even still, after he turns into a shibito he remains attached to Harumi. From the line you can hear him say in the Shibito nest - "I smell a Harumi..." - perhaps you can interpret this to mean that he has a hidden dark side.
[No. 009] Tamon Takeuchi's Faculty ID
According to his ID, Takeuchi is a professor of folklore at Josei University's cultural anthropology department. After losing both of his parents in the 1976 landslide he was raised by a relative, later paying his own way through university; since he specialises in folklore, he probably ended up on this path due to being a Takeuchi (his father, Omito Takeuchi, was a local historian. Through independent research he pursued the secrets of Hanuda Village, describing them in the "Takeuchi Monographs"). It is obvious that Tamon himself has some degree of knowledge about Hanuda Village's secret ritual, but what is actually one of the biggest mysteries in Siren is whether someone told Tamon about the ceremony 27 years ago. Since an urban university student picked up so quickly on the secret ritual, lurking beneath the water's surface, perhaps this is just an episode that tells of how excellent of a researcher Tamon is...
[No. 010] Megalith Fragment
A piece of the Mana Stone, worshipped by the villagers of Hanuda as an object of their faith, Manaism. The Mana Stone is a huge rock on a sandbank in the Mana River. It is pyramid-shaped, and seems more metallic than rock-like. It is also known as the "Stone of the Descending God", so when comparing the information from "[No. 001] Irazu Valley mural" there is the possibility that it fell from space along with Datatsushi - in other words, that it is part of a fallen spacecraft. You can also see a mysterious body of light in "Strange Tales of Hanuda" Chapter 1 and "[No. 027] Commemorative Photo of Opening". Perhaps... this means that the area around Hanuda Village has long been a flying path for mysterious bodies of light?
[No. 011] Well Idol
The "Baby on the Chopping Board" legend mentions the taboo of eating something that should never be eaten, symbolising something quite characteristic. The "half human half fish" mummy impaled on the plank clearly reflects the memories of Datatsushi, being eaten alive, on a piece of wood that used to be a Mana cross. However, what the idol is actually doing at the bottom of the well is never really explained in-game. Perhaps due to the "original sin" of eating the flesh of the god (Datatsushi) long, long ago, which will never be forgotten, someone left the idol there. Also, to make the idol look so realistic a variety of materials were prepared, and the development staff actually hand-made it. As producer Fujisawa mentions in the interview, they took the tail of a fish bought for 180 yen and used it to create the idol's lower body.