Serizawa Suzume (芹沢雀 Serizawa Suzume) is a supporting character in the 3rd entry of the Gintama Chromatic Chronicles series, which is a crossover with My Immortal . He is captain of a Shinsengumi squad consisting entirely of OCs in charge of exterminating Mary Sues and other fan-made elements that prove detrimental to the Gintama canon. He is otherwise known as a Fan Dumb Exorcist.
He is described as having curly strawberry blond hair and looking very French. While on duty, he normally wears the standard Shinsengumi uniform, but he also changes into an Exorcist uniform consisting of a white robe described as similar to that of Saruman from Lord of the Rings (misspelled as "Sarumen") and giving him an angelic appearance.
He is a decent and polite man, which makes him completely different from his historical counterpart, a fact he himself is aware of. He also states he hates the historical figure he is based on and intentionally works to set himself apart from him. He shows more responsibility and dedication to his work as a Shinsengumi officer than his friend Yamanami. He also exhibits snarky behavior towards the fanfiction author and his friend.
He is the only Shinsengumi member to have received some form of formal education. According to Kondō, he has graduated from a "wizarding school". Aside from his work as an officer, he is also affiliated with the PPC .
He is introduced in the My Immortal crossover being tasked, along with Yamanami, to supervise the fanfiction author, who is under the influence of the goffik virus and is slowly becoming insane. His interactions with the author and Yamanami is chronicled in the author's notes. Near the end of the story, he appears in the story proper, facing off against the advancing army of goffs, then Okita who has managed to subdue Ebony Dark'ness Dementia Raven Way and wants to use the goff army to his advantage and kill Hijikata, but his exorcism proves useless against Okita. After Ebony is defeated by Takasugi Shinsuke and the goffik epidemic is solved, Serizawa is shown to be infected himself and is presumably the only infected person left in Edo.
- Kondō and Hijikata: His superiors, though he seems to be on better terms with the former than the latter. Kondou calls him "Jackie" due to the fact his first name can also be read as jaku, while Hijikata constantly throws insults at him as well as Yamanami over the course of the story.
- Yamanami Kei'ichirō: His friend, though he seems to be more responsible and courteous than him as opposed to Yamanami's obnoxious behavior. It is unknown whether Yamanami is part of the Sue Slayer Squad. Both of them are given the task of supervising the author. When Yamanami goes missing without any readily explained reason at the end of the story, he promises Hijikata that he and his squad will immediately investigate his whereabouts.
- Okita Sōgo: His fellow Shinsengumi member. He finds himself facing off against him after Okita learns all of Ebony's techniques and takes over her goff army.
- Takasugi Shinsuke: He opposes him as do other Shinsengumi officers. He is shocked by the fact Takasugi is able to take down Ebony despite not being a Fan Dumb Exorcist.
- Ebony Dark'ness Dementia Raven Way: Even after she is erased from existence, he is infected with her virus and is presumably the only infected person left.
- The fanfiction author: He and Yamanami are tasked with keeping her in check, thereby preventing the story from turning out badly. When questioned as to why he is given such a mission instead of chosen to exterminate Ebony herself, he responds that it is entirely the fault of his superiors.
- He is based on Serizawa Kamo (芹沢鴨), the historical Shinsengumi member.
- His first name, Suzume, literally means "sparrow" and can also be read as jaku, hence Kondou's calling him "Jackie" and the author calling him "Jack Sparrow". In real life, Suzume is more likely a female name.
- His favorite food/drink is amazake, and he seems to have extremely low tolerance for alcohol, as seen by his blushing from merely consuming amazake, which has little to no alcohol.