|First Appearance||Chapter 96|
|Last Appearance||Chapter 202|
|Status||Wanted serial arsonist |
Member of the New Bloodline
|Known Relatives||Homura Tetsuyuki (nephew)|
Zenjirō Kasai appears to be a man in his late thirties or forties and is the uncle of Homura Tetsuyuki. Kasai wears a black cap with the word 火 (the kanji for fire) on it. He is rarely seen without his cap, which hides a burn scar which Sicks had given him on his forehead. Kasai is usually seen smoking cigarettes in most of his appearances and frequently gets more boxes when his stock finishes. His laugh, hi hi hi, uses the japanese kanji for fire.
Kasai is a calm and collected individual in most of his appearances. He rarely panics and is cunning and shrewd. Kasai respects Sicks quite a bit, though he describes Sicks as a completely evil and disgusting being, and is not as loyal to him as Genuine is, something she would often scold him about. Kasai looks down on the police department, stating they're only capable of controlling road traffic and catching minor crooks. He is so confident on the police department's incompetence that he dares to walk around the city in public even though he is a wanted criminal.
Not much has been revealed about Kasai, but he was a wanted serial arsonist prior to his introduction as a member of the New Bloodline. Kasai was encountered by Sicks when he was commiting what would have been his final arson as he originally planned to kill himself in that fire. This encounter with Sicks gave Kasai a new will to live, and Kasai joined the New Bloodline. Sicks had Kasai follow him during his meeting with Genuine, though during his later meetings with DR, Tierra and Vijaya Genuine took Kasai's place instead.
Unlike the rest of the New Bloodline who used elements, Kasai does not have direct control over fire. He uses a complex series of tubes on his body to create flames and eject them towards his targets. Like DR, Vijaya and Tierra before him, he has a good amount of knowledge on his element and knows how to manipulate fire to cause explosions or to trap his enemies. While Kasai had X's cells implanted within his body, he was reluctant to do so, resulting in Genuine often chewing him out for not being "loyal enough" to Sicks. In chapter 185 Kasai says that his natural power is psychokenisis. It is a possibility that when he was sitting in a burning building, a chunk of burning concrete was brought down by his psychokenisis.
Kasai is first mentioned by Higuchi as the uncle of Homura Tetsuyuki, though he doesn't actually appear until much later after the whole HAL arc. He meets up with Homura to see if Homura is capable enough to be his partner. When he sees Homura isn't fit for the job, he wishes him a peaceful life and leaves.
Kasai is later seen with X, apparently joining his group at one point, when he obtains HAL's Eye. After X is captured by Sicks, it is revealed that Kasai got close to X to collect information for Sicks, attempting several times to leave X 'alone', specially from Ai, whom under any circunstances did not take her eyes of X; and was kicked out of the group before he could inform Sicks of X's location. From this point on, Kasai is assigned to assist the other members of the Five Fingers in their duties. He helps set up Sicks' logo before the other members begin their work. After Neuro defeats DR, Kasai kills DR for his incompetence and takes a picture of DR burning to death for Sicks to see. Kasai doesn't do much during Tierra's attacks except setting up Sicks' logo and having small talk with Tierra. Kasai helps Vijaya in his attacks later, but leaves Vijaya to deal with his opponents after he decides to get serious.
After Genuine is defeated, Sicks comes over to Japan and tells Kasai it is time for him to begin his attacks. After receiving the orders, Kasai attempts to kill Sicks to fulfill his wish of living longer than him, but Sicks survives without a burn and tells Kasai to just do his job. Kasai goes around Tokyo after this, setting buildings on fire. He encounters Yukinori Hayasaka during one of his attacks, but easily defeats Yuki before he could even do anything.
After Sasazuka's death, Usui, Tsukushi and the entire police department become determined to put an end to the New Bloodline and they hunt down Kasai with some help and instructions from Neuro. Kasai becomes overwhelmed when the police forces outnumber him, and attempts to escape, though Higuchi manages to pinpoint his locations by monitoring him with CCTV cameras. Kasai escapes to the top of the building and Shura appears just in time to help Kasai. The situation is quickly turned around again however when Hisanori Hayasaka emerges from the sidelines and blasts Shura to avenge Yuki (who Kasai severely injured). Kasai is continuously shot by the polive forces after this. Usui notices Kasai's lack of resistance however and Kasai reveals he had climbed to the top of the building as he knew if he was going down, he would bring everyone else with him. The entire building bursts into flames and Kasai is seemingly killed by the falling debris.
In the 3-year timeskip at the end of the series, Kasai is shown to have survived the explosion, fulfilling his ultimate wish of outliving Sicks.
- Kasai is the first member of the New Bloodline to be introduced in the series.
- He is also the only one shown to have survived at the end of the series.
- In the Volume 20 cover, he is shown with a no smoking sign on his hand.
- His cigarette brand is a discontinued series called Ji-oker and he has 20,000 packs stored in his fridge at home.