Mamoru Itsuki
Mamoru itsuki
AppearancesForbidden Siren 2
Voice ActorTakumi Saito

Mamoru Itsuki (一樹 守 Itsuki Mamoru?) is the main character in Forbidden Siren 2. A trainee editor at the mystery science magazine "Atlantis". As he is visiting Yamijima Island conducting solo research the young man becomes caught up in the strange events, and meeting Yuri Kishida is what leads him into the midst of the darkness.


Mamoru is a person who looks at things from a logical perspective, thinking of how to explain supernatural things in a down-to-earth view. However, as he faces the creatures on the island, he accepts the situation he is in. He has the image of being incredibly interested in the occult and occasionally running wild, but in actuality he is a perfectly sane and completely normal young man interested in modern literary arts.

Another, less noticeable part of Mamoru's personality is that he is literal-minded. In a talk with Ikuko at the docks before going to Yamijima, he takes a joke Ikuko makes about swimming to the island literally, even calculating the distance of the island and wind direction. 

After releasing Mother, Mamoru is filled with anger towards her, Yamirei and Yamibito, as well as guilt for being fooled by Yuri to begin with. When he enters the Bright Win, he wishes to eradicate every Yamirei he can find, calling them "Beasts from hell".


Having got a part-time job at the editing department of Atlantis,
Mamoru full body
his favorite magazine since he was a child, Mamoru pursues his hobby at work, and gets the chance to work on books, which has been his dream more than anything else, and works as hard as he can in the editing department. His passion is acknowledged by his boss, and he takes a job at Super Scientific Research Co. upon graduating from a specialist school (the company generally only hires employees who have graduated from university, so he is a special case). However, though he performs well at his job he has no real-world experience to prove himself as a journalist in things such as setting up his own plans and collecting info or articles. Feeling that neither he or the editor-in-chief will accept him if he simply sits behind a desk, and believing he should be doing more, when called to a meeting he makes unreasonable demands, such as asking to be allowed to go and conduct research in Egypt (for which they actually did not have the money), and running wild due to his youth (of course, his youthful drive appeals to his superiors).

Forbidden Siren 2Edit

Along with Shu and two other passengers, Mamoru took a boat, the Shoseimaru, to Yamijima Island when a freak storm knocked them over. Coming to on a pier to the island, he found his way to the Materials Warehouse, where he found Yuri unconscious. After saving her from a crazy man, the two escaped the harbour. When they reached the Shinari Mountain Trail, Yuri said that her mother was being held against her will on that island, and that only he could help her. They were soon found by two army men, but they were suddenly rushed by a great red tidal wave.

Mamoru came to, and he and Yuri ran away from a woman attacking them. He learned that he was able to sightjack since the tidal wave uses it to navigate through the hostile citizens.

Having removed the seals on the "seven gates" and making the descent to the Netherworld, Mamoru is saved by Ikuko as he is about to be sucked in by Mother, and realizes that he has been used by Yuri. He takes responsibility for this by destroying the seven stone markers, although he realizes that it will do nothing to help the situation and feels an intense sense of blame (naturally, since Shu Mikami and Soji Abe also made the descent together it wasn't just Mamoru's fault). Reaching his physical limits and mentally exhausted he almost gives up, but as he learns the true nature of the Yamirei and Shiryo as he wanders the island (that they are monsters that are weak to light, and can be defeated), he gradually begins to fill with anger towards the one who made this happen. Through meeting Yorito Nagai, a comrade from the same world as him, and Ikuko Kifune, a girl with strange abilities, he regains his strength and uses his unique, characteristic point of view (reasoning) to find an end to these strange events.