Former member of the Main Cast
Itsuki has short brown hair that is parted at the right side and hangs down over his face with a curve at the right side, gray eyes and round glasses.
So far, he has only been seen in his school uniform.
Itsuki is a polite, kind and sensible person who is very loyal to his classmates (as seen in Episode 9) who also has a crush on Saya Kisaragi (which she doesn't seem to notice).
In reality, Itsuki is a part of the Main Cast, although his personality appears to change little afterwards. It is never revealed what motivated him to join but it may have been undercover work on the orders of SIRRUT.
Despite his apparent allegiance, his feelings for Saya Kisaragi were genuine as he confesses that he really does love her right before he dies, making him the only known cast member that was in part at least not acting.
Itsuki is first seen interrupting Saya Kisaragi, Yūka Amino, Nene Motoe and Nono Motoe's little 'routine' to tell them that the teacher would be coming to class soon. Saya apologizes for them being too loud but Itsuki says that it was fun to watch their little routine and that good comedies really needed a straight man. Yuuka gets angry at this but then Ms. Kanako Tsutsutori comes into the classroom and everyone took their seats. After the school day was over, he asked Saya if they wanted to go home together because he found a good place that sells cake. Saya says that she would love to but she ha
s a ceremony to prepare for at the shrine so she has to go home early and he says that that's too bad. Saya states that she really wanted to eat cake with him and he asks if that was really it but Saya didn't hear what he said so she told him bye and ran off.The next day, he asks Saya what kind if marks were on the dog she saw. Saya greeted him as 'class rep' and he said he'd be happier if she called him by his first name.She then states that she could also call him 'class rep Tomofusa', but Itsuki says that's not what he meant. The twins start to joke around but Itsuki says their good at ignoring you it only makes you try harder and they cheer him on. Kanako comes into the classroom saying it was time for homeroom.
The next day Itsuki, Saya, Yūka, Nene and Nono are all seen eating lunch (Itsuki's plan to get closer to Saya) outside. He asks Saya if she made her lunch and Saya replies that Fumito Nanahara made it for her.After finding out who Fumito was he stated that he sounded younger than her father and Nene and Nono said that he still had a shot and he said he'll try his best.When Saya asks everyone if they knew what a Guimauve was and if so what did it feel like Itsuki says that
he hasn't ever tried one. Nene and Nono said that it felt like a kiss causing Saya to blush and they both told Itsuki "good for you!" and he said he'll try even harder. After that they start talking about how the town only had one of everything and Itsuki asks Saya if she likes the town and she says yes. Itsuki along with everyone else watch as Saya talked to Tokizane and Nene and Nono said that she may be starting another route and Itsuki just smiles at this. Saya then runs back after talking with Shinichirō Tokizane but trips and falls and Itsuki and the others get up in surprise at this. He is seen the next day walking with Saya, Nene, Nono and Yūka to go to their usual spot to eat lunch and are seen talking about the missing baker. He asks if the bakery was closed and Nono replies that it looked like he never came back because she heard someone went to buy bread but couldn't.
Itsuki states that the police officer went out of his way to warn them so he must have been looking for him but Nono says that they couldn't find him. After Nene asks what else would be a good name for an adult running away, Itsuki said the word they're looking for is disappearing to which they all agree. Later, he is seen with the others wondering where Saya ran off to saying she was chasing a dog.
In Episode 8, he is present when the Spider appears and in Episode 9 helped as much as he could, going so far as to put himself in harm's way for his friends and classmates. Along with Saya he is the only other student to survive the attack as everyone else (including Yūka) are killed by the Elder Bairn. Kanako Tsutsutori and Tokizane were the only other characters to not be killed but were not present at this time.
In Episode 11, both he and Yūka confront their former "classmates" who along with their teacher (Kanako) plan to speed up or rather put a stop to the game (created by Fumito). During this time he reveals his disappointment as he was not actually killed off yet.
In the finale he alongside Yūka are the only main cast members to survive Fumito's betrayal as the others were all killed for not sticking to the script. Although he did not intervene on behalf of his classmates, when Saya was confronted by Fumito's army, Itsuki threw a soldier that was shooting at her aside in order to protect her. He was then shoot repeatedly in the back, whilst trying to reach Saya, for this selfless act.
As he lay dying Saya knelt beside him, and he took this opportunity to finally confess his feelings, admitting that his love for her was genuine, When Saya stated that he never knew the real her, Itsuki admits that while that may be true he still believes that the girl he fell in love with to be a part of Saya, indicating that he still cares for her despite her shift in personality before he then succumbs to his injuries.
His death appears to further harden Saya's hatred of Fumito; as the master mind of this whole scheme was now directly responsible for the deaths of both her adopted father Tadayoshi Kisaragi (who likewise truly appreciated Saya and viewed her as his daughter) and Itsuki; the only human in the entire world known to have actually cared about her (at that point).
The Last Dark
In the movie, it was revealed that despite being a member of the main cast, Itsuki worked as a member of SIRRUT. He deliberately hacked the cameras and was able to send information to the group about Fumito Nanahara and his goals.
Since Itsuki has a crush on Saya, he tries to act cool in front of her (which usually doesn't work). He also cares for her but he rarely does many things to show it. He later sacrificed himself when one of Fumito Nanahara's soldiers was about to shoot her, confessing that he did it because his feelings for her were genuine.
Although Yūka and Itsuki were often seen together, they don't interact with each other, but they were both present when Fumito Nanahara confronted the others who were trying to put an end to the game. Yūka for her part did nothing to help save Itsuki after he was shot.
Nene Motoe and Nono Motoe
They root for him and they seem to get along well, but as they are characters for the Main Cast, it is unknown how they really felt about each other. Never the less, Itsuki did nothing to help prevent their deaths.
- The name Itsuki means "deviate, idleness, leisure, miss the mark, evade, elude, parry, diverge" (逸) (itsu) and "tree" (樹) (ki).
- Itsuki's surname Tomofusa means "sheath, scabbard, margin" (鞘) (tomo) and "total, gross, general, all, whole" (総) (fusa).
- Atsushi Abe described Itsuki as a distinguished figure who is overly quiet about his feelings.