|“||I know it may sound ridiculous / Unlike the rest of you, I don't believe in those paranormal craps / But what we're seeing now is definitely not reality||”|
—Shinichi Yanagihara, Corpse Party: Another Child 1 (Chapter 3; Encounter)
Shinichi is a teenager with short blackish-brown hair swept back with brown eyes. He wears the Satsukiyama Academy school uniform consisting of a brown double-breasted jacket, a white shirt loosely collared with a black necktie, and black pants with matching shoes.
Outside of his school uniform, Shinichi wears a long-sleeved tartan shirt over a black shirt with pants.
Although his acts and attitude seem somewhat brash, Shinichi will openly show his concern for others when worried about them. It is also shown that previously Shinichi had a girlfriend whom he recently broke up with. There are rumors about him having a crush on Erina Yuzuki.
Corpse Party: Another Child 1
Shinichi was compelled to take the Sachiko Ever After ritual by Erina when he came to check on Yuuma and Tamaki behind the school building. He was consequently trapped inside Heavenly Host Elementary School afterward.
Shinichi found himself in a classroom with five other classmates: Kana, Minoru Hasegawa, Noriko, Yamazaki, and an unnamed fifth student. He later joined Tamaki and Miyako Hayakawa to search for Yuuma, leaving the classroom and the other classmates behind. Shinichi already figured out that you can't break the windows or doors in Heavenly Host, which he demonstrates to Tamaki and Miyako by grabbing a chair and smashing it into the window and the chair breaks, leaving no scratch.
A moment later they heard Minoru screaming and they run back to the classroom. Shinichi tries to open the shut door, but is unable too, and a splash of blood appears on the doors window. A bit frightened by the sight of it, Shinichi asks for a response and all he hears are death cries. When the screaming finally stopped, the door unlocks and he opens it to see everybody murdered except for Minoru, who when asked what happened, starts laughing maniacally. Minoru's head is then ripped in half by an unseen force.
Suddenly they hear a laugh and something approaches Shinichi. Tamaki says that they had to run away because it was dangerous and so they did. After retreating, they stop and Shinichi angrily asks who's behind all of what's going on. After comforting Tamaki, saying it was his fault for leaving the students in the classroom and not her's, Tamaki goes to the girls' lavatory. He and Miyako discuss whether what attacked the classmates was human or not. Miyako goes to check on Tamaki, but first Shinichi wants to know if the rumor about Erina picking on Tamaki is true. She answers that Erina has her reasons for that.
Corpse Party: Another Child 2
Later the three wander in the halls for quite some time, not being able to find anybody. Shinichi notices a library and they go in finding papers about the murder case. While the girls rest, Shinichi goes to read some books to maybe find a clue about how to get out of Heavenly Host. After the girls are done talking, Miyako goes to help Shinichi. After noticing someone, she calls out to him, but it appears to not be him but the girl in black. After Miyako remembers who the girl was, she gets possessed and she runs to the children spirits, and the door locks. Shinichi mentions that they could be the same children from the murder case. They waited for hours at the door, but it wouldn't budge an inch.
They eventually leave, arriving at the infirmary. They hear voices coming from inside and Shinichi goes to check alone. Suddenly the voices stop and Naho Saenoki pops up and reveals some important information, as well as the fact that she herself is a spirit. Questioning himself if Naho could be a ghost, they meet Mayuri Yoshimura, a classmate of theirs. After hearing most of the details they needed to know, Shinichi thinks they're "supernatural geeky bitches" and refuses to believe it. He tries to encourage Tamaki to not believe what Naho is saying, but because it is Naho, Tamaki believes it right away. Tamaki also understands that Naho is a ghost and asks if she has met the one she was trying to find. Naho says that she did, but it was already too late.
When Naho leaves, Shinichi leaves for the bathroom, and Mayuri tells Tamaki that Shinichi was the one who told Erina and herself that Tamaki could feel spirits. When he came back from the bathroom, Tamaki was talking to Saki. He shockingly asks why Tamaki isn't afraid of her to which she doesn't answer to.
While looking for his friends with Tamaki, Shinichi was pulled down a hole by Yuki Kanno and Ryou Yoshizawa. They then used scissors to stab him in the leg, and he falls down safely into a pile of corpses.
Corpse Party: Another Child 3
Shinichi then appears after the spaces merge, saving Tamaki from a darkened Erina, who accidentally stabs him in the back. Erina kills herself and Yuuma, Shinichi and Tamaki are left together. Tamaki gets taken by the girl in black and Yuuma runs after them. While Shinichi waits, he talks with the now purified Yuki about how to undo the charm. After some time, Yuuma gets back with Tamaki, and Sachiko Shinozaki wakes up and finds all of them. Shinichi tells how to undo the charm, but Sachiko already walks closer to them. Saki appears once again, saying that she will protect them. Shinichi and others undo the charm and the three wake up in the place where it all began -- behind Satsukiyama Academy. They meet one of their teachers and as they try to tell him what happened, the teacher gets confused as he doesn't remember any of the dead students.
Some time later, they all burned their paper doll scraps, as they won't need them anymore.
Corpse Party: Another Child