|Base of Operations||
Light Music Club room
Seven New Witches Arc
Inside a room, Sid and Nancy discuss the events connected to Ryu and Tsubasa, denoting that he is the cause behind her removing her power from the basketball team. Noting as well that Toranosuke and Jin followed his orders similar to Tsubasa's. Nancy states they have made a discovery, she comments that he is a first-rate Psycho, with him returning the compliment. Later, Sid and Nancy appear from behind bushes, telling Ryu that they saw his and Urara's conversation. He questions their identity, he jokes with Nancy, accidentally revealing their names. After Ryu informs Nancy that altering the school uniform is against the rules, he agrees with her statement that the punk spirit lives forever. As Ryu intends to leaves he grabs him as Nancy ask for his identity, claiming that she will erase his memories if he does not cooperate.
As Nancy explains Kotori's power to Ryu, Sid clarifies that just by kissing the doll someone will be put under her spell without getting a direct kiss. He then watches as Ryu stomps away to copy Kotori's power. Later by lunch, he and Nancy spy on Kotori, noting that she's by herself in the courtyard. He doubts Ryu, and asks Nancy how he's going to kiss the doll. He then sees Ryu coming noting Nancy, however they are surprised to see him bring a doll. They watch as he uses the doll to introduce itself, surprising them more.
After seeing that his tactic work, he notes that Shoba is disturbing. As Ryu calls them that he managed get a kiss from Kotori, he is impressed, not being able to believe that he did it. However as Nancy informs Ryu that he didn't copy Kotori's power, Sid asks Ryu to stop using Shoba. After they finish their conversation, he is called by Nancy as they leave.
Later he listens as Ryu begs Nancy to introduce him another Witch. She doesn't understand what he means, he helps by clarifying that he wants to over-write the power. He asks why he didn't ask Tsubasa, however he explains she's on the road for a game and won't be back soon. As Ryu asks why they monitor the witches, Nancy remembers they haven't told him which she begins to explain that she can also tell which students have been put under their spell, which she reports it to Sid. He explains that he manages the information and turns it into charts and graphs on his laptop which he shows, shocking Ryu how easy it is to understand. He cheerfully notes that he makes full use of Excel and Powerpoint. Ryu puts it into short and tells him that if it would change there would be a problem. After Nancy denies his request, he grins ad asks him to clean the club room.
After Nancy angrily left the room, he stops him albeit crying. He quickly gets to his laptop and searches for a witch, asking Ryu to keep it a secret. Ryu asks why he would do it, he explains that he was following him while he was with Kotori and noticed his feelings for Urara and was moved by seeing it. He then tearfully states that he is in love with Nancy. They then shake hands, forming an alliance as they both seem to understand each other. He then tells him the witch that can predict the future, claiming that it would be easy for him to copy. Ryu worries as he states he doesn't want to see a future he can't change, Sid however explains that the power allows one to see the future and easily change it. They then leave the room and they enter the Library, he notices however that she's not there. Ryu asks why the witch would let him copy her power easily, he explains that she has no objectives to kissing. As She enters he informs him her name and grade, being Aiko Chikushi of Class 2-G. As Ryu is surprise that she isn't opposed to kissing, Sid jokingly states that it gets him excited which the former denies it. He then informs him that she treats her power like a business as she will kiss whoever pays her.
Winter Break Arc
He and Nancy are informed by Ryu that he is back with the Student Council, with Nancy announcing that their relationships ends there. He starts sobbing, hugging Ryu stating that they just became friends. He then watches as Nancy asks Ryu if he had just been with them on a mission. He watches as Ryu asks Nancy, what she had meant if he remembers her, confusing him. He and Nancy then leave as Ryu argues with Ushio.
Later as Ryu searches for clubs to switch dates for the winter trip, he asks him and Nancy. However Nancy tells him that they don't do any club activities, he also remarks that he can't play an instrument.
Second Witch War Arc
Much later as Nancy the other witches to come to the Light Music Club room to inform them that they will do a ceremony to get Ryu's memory back. He holds up his tablet on a table for Akane to converse with them. 
Much later as Nancy calls the other witches to come to the Light Music Club room to inform them that they will do a ceremony to get Ryu's memory back. He holds up his tablet on a table for Akane to converse with them. 
On the Election Day, during the voting he gets his memories of Nene's speech erased by Ushio, forgetting him, Masamune and Ryu.
Stolen Notes Arc
After a day of school, Sid asks Nancy on where she's going. He is shocked to hear that she still wants to sing. He points out that they only formed their club's band that day, being backed up by one of their new members. He states that her response is mean, which she joyfully says she was kidding as they leave.
Recovering the Lost Memories Arc
After Shinichi wishes to bring back all the memories, Sid starts to remember all his erased memories. Which some time after, he and Nancy visits Ryu about this, as Nancy complains about it to him.
Book-Keeping Skills: Sid is also great with his laptop, as Nancy's power allows her to detect the number of people under a specific Witch's power. She periodically collects and gives this information to him, who then organizes it in his laptop and compares it against its historical values, looking for anomalies in the time series that would betray a change in the use a Witch gives to her power and thus a potential problem. This was able to suitably impress Ryu.
Witch Locating: Sid was able to locate any of the Witches and Witch Killers of Suzaku High. He also seems to be able to find them outside of school, having found Ryu when Nancy wanted to erase his memories. He was also able to locate Aiko Chikushi, who went to the Library.
Laptop:Sid uses this to make charts of the individual witches' use of their powers and then comparing them to previous values. Checking for differences in the time series that would betray a change in the use a Witch gives to her power and thus a potential problem. It is known to have Excel and Powerpoint.
Tablet:Sid used this to operate a video conversation with Akane, who was absent that day, so she could inform the witches of Nancy's set on the time the ceremony will be placed due to her busy schedule.
Appearances in Other Media
Another of the Suzaku Festival: Sing! Dance! Paranormal Research Department!
- ↑ 1.0 1.1 Yamada-kun to Nananin no Majo Manga: Chapter 102, Pages 1-2
- ↑ 2.0 2.1 Yamada-kun to Nananin no Majo Manga: Chapter 102, Pages 17-20
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 105, Pages 2-6
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 105, Page 8
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 105, Pages 11-13
- ↑ 6.0 6.1 6.2 6.3 Yamada-kun to Nananin no Majo Manga: Chapter 108, Pages 10-13
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 108, Pages 14-20
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 111, Page 13-14
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 114, Page 11
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 156, Page 3
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 156, Page 3
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 172, Page 15
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 174, Pages 8-10
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 224, Pages 6-7
- ↑ Yamada-kun to Nananin no Majo Manga: Chapter 225, Page 5
- ↑ Yamada-kun to Nananin no Majo OVA: Another of the Suzaku Festival: Sing! Dance! Paranormal Research Department!