Houshou Takigawa (often called simply Monk, or Bou-san in Japanese) is a powerful Buddhist exorcist working for SPR. Before the series began, he was a monk at Mt. Koya. It is later revealed, however, that he only became a monk because his family owned the temple. His real job is as a studio musician; he plays bass.
He will be portrayed by Yosuke Kawamura in the live action.
Takigawa was hired by the principal of Mai's school, along with Ayako Matsuzaki, John Brown, and Masako Hara when the principal had concerns about Naru's age. Unlike John, Takigawa preferred not to work with SPR at first.
Takigawa (who the others began to call "Bou-san" or "Monk") is often the character who accompanies Mai and Naru on their primary visit to a case, as seen in Volumes 3 and 4. In Volume 3, it is revealed that being a monk is more of a "side job," and that Monk's primary occupation is as a studio musician. He claims that the only reason he became a monk was because his family lived at the temple. He quit when he found out that monks aren't allowed to bring music CD's to the temple. Because of this, though, he is always getting requests from people who need spiritual help. A fan of his band is the one who asks him to take the case "After-School Hexer."
When Mai expressed a desire to learn how to do an exorcism in Volume 4, Monk is the one who initially teaches her. Later, Mai attempts to exorcise spirits who are much too strong. She is saved by Monk, who berates her for being so foolhardy. He also comforts her and counsels her to "have faith in Naru" when they attempt to turn the curse onto the students.
During the "Blood-Stained Labyrinth" case, Monk is often seen surveying the mansion with Yasuhara, John, and Mai. He also does much of the physical work, such as breaking down walls.
In Volumes 8 and 9, when Naru is possessed, Monk steps forth as a leader for the group. He makes the majority of the decisions regarding safety, and decides to call in Yasuhara for his research power. These decisions are a large part of how the case is solved. Monk is greatly injured fighting off spirits, but still manages to attempt an exorcism on a god later in the manga. It is Monk who first becomes suspicious of Naru's secret identity, and in Volumes 10-12 is often seen in secret discussion with John and Yasuhara. Together, the three of them discover that Naru is really Oliver Davis. In volume 12, Yasuhara pressures Naru into staying to listen to their theory, and Monk lays out their evidence, which convinces Mai, Ayako, and Masako that they have discovered the truth.
Monk is a very genial person who gets along well with most people, although he often provokes and bickers with Ayako. He is also very good with kids, as seen in the "Silent Christmas" case (Vol. 4), and serves as an older brother figure to several people throughout the manga. He often jokes during cases, especially with Mai, and is very playful. This attitude is perhaps best personified by his "Bandit Spirit" (a play on "Japanese Spirit) shirt, which he wears in Volume 6.
When the situation becomes serious, however, Monk becomes more somber, and shows his true intelligence. He has a very good understanding of spirits and psychic phenomena, and is usually the one who explains events to Mai or clients.
Monk is a very strong, skilled exorcist. Although he cannot exorcise people (like John can), SPR can usually rely on him for exorcising places using Buddhist chants. In Volume 11, Naru and Mai examine Monk's tokkosho, a Buddhist tool he used in his exorcisms. When Naru held it, he sensed Monk's energy (presumably using psychometry, though this is not clear), and commented that even he had been underestimating Monk's strength.
Monk has proven himself to be very useful in dangerous situations; he is the first one on the scene when a spirit dog bites a girl in Volume 4. He also defends the entire family and SPR in Volume 8 when they are attacked by multiple violent spirits, although he is injured himself. In Volume 11, Monk is the last person besides Naru and Mai to "disappear." He throws his tokkosho to Mai and Naru so that they are not left defenseless.
Mai and Monk have a close, sibling-like relationship. He often explains things to her, and counsels her whenever she is having a rough time. Mai respects his advice, and he tries to cheer her up whenever she is down. They are often seen joking together, and Monk twice offered to date/marry her: once, when she was upset at Naru and Masako, and once when he found out she was an orphan. This last incident seemed to affect him particularly, as he himself often takes on a fatherly role towards Mai when things got dangerous. He sometimes calls her "jou-chan," an affectionate way to say "young lady."
Monk appears to be one of the few people whom Naru truly respects throughout the series. Unlike Ayako, he is never seen questioning Monk's skills as an exorcist, although he occasionally shows impatience with Monk's lack of seriousness. In turn, Monk has a high opinion of Naru's skill as a psychic researcher. He refers to Naru as "Naru-bou," and in response to Naru's lecture on spirits in Vol. 10, says "I think you're pretty amazing." Naru seems to be genuinely gratified by this compliment, despite his usual arrogance. He doesn't like the way Naru treats Mai and wishes that he had more respect for all of them
Ayako and Monk are often seen bickering throughout the series. A large part of this is because, up until Ayako's successful exorcism in Vol. 9, Monk doubted her strength as a miko and an exorcist. He seems to enjoy teasing her, and she is certainly not afraid of retaliating physically. Despite this, they do work well together. Multiple times, it is commented on by other members of SPR that the relationship between Monk and Ayako is that of an "old married couple".
Although they appear to be very different, Monk and Yasuhara get along very well. Monk is impressed by Yasuhara's efficiency and intelligence. He is the one who contacts Yasuhara in Vol. 8 when he believes that the group needs more support in order to solve the case. The two have similar senses of humor, illustrated best in Vol. 10. In addition, they occasionally make jokingly homosexual remarks to each other. In Vol. 4, when Monk teases that Yasuhara likes Mai, Yasuhara replies "But I like you even more," and in Vol. 9, Monk calls Yasuhara a pervert for trying to take Monk's shirt off in order to treat his wounds. Similar to how he addresses Mai, Monk often calls Yasuhara "shounen," which means young man (although the term usually applies to people who are 15 or younger).